JP2007194612A - Semiconductor device or manufacturing method for semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor wafer by which a slurry adhering to a rear surface of a semiconductor wafer is removed without fail without enlarging a device. <P>SOLUTION: The rear surface of a semiconductor wafer W is sucked by a sucking part 21 of a first polisher to polish an outer periphery of the semiconductor wafer W, and then the semiconductor wafer W is detached from the sucking part 21 of the first polisher. Then, the semiconductor wafer W is arranged above the sucking part 21 of a second polisher with a specified gap. Water is ejected from the sucking part 21 of the second polisher to wash the rear surface of the semiconductor wafer W. Then the rear surface of the semiconductor wafer W is sucked by the sucking part 21 of the second polisher to polish the semiconductor wafer W. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device or a semiconductor wafer.

Conventionally, in the manufacturing process of a semiconductor device, the surface and the outer periphery of a semiconductor wafer are polished.
Polishing is performed by adsorbing the back surface of the semiconductor wafer to the adsorbing portion. Here, the slurry generated when polishing is performed around the back side of the semiconductor wafer.
When the polishing is performed by adsorbing the back surface of the semiconductor wafer to the second adsorbing portion for carrying out the next polishing while the slurry is adhered to the back surface of the semiconductor wafer, the slurry adhering to the back surface of the semiconductor wafer becomes the semiconductor. It adheres firmly to the backside of the wafer.
Therefore, for example, after the back surface of the semiconductor wafer is adsorbed by the adsorbing portion and the outer peripheral portion of the semiconductor wafer is chamfered and polished, the semiconductor wafer is submerged in the water tank while adsorbing the adsorbing portion, and the adsorption portion is rotated. As a result, a method for removing the semiconductor wafer and slurry adhering to the adsorbing portion has been proposed (see, for example, Patent Document 1).
In addition, for example, a method has been proposed in which a semiconductor wafer that has been polished is removed from the adsorbing portion, submerged in a water tank, and the back surface of the semiconductor wafer is subjected to shower cleaning and scrub cleaning (see, for example, Patent Document 2).

Japanese Patent No. 3649531 Japanese Patent Laid-Open No. 2005-74574

However, the methods described in Patent Documents 1 and 2 have room for improvement in the following points.
In the methods described in Patent Documents 1 and 2, when removing the slurry adhering to the back surface, both use a water tank, which leads to an increase in the size of the manufacturing apparatus.
In the method described in Patent Document 1, since the semiconductor wafer is adsorbed on the adsorption part and submerged in the water tank, the slurry that has entered between the adsorption part and the semiconductor wafer cannot be removed.

  According to the present invention, the first machining step of machining the semiconductor wafer by adsorbing the back surface of the semiconductor wafer to the adsorption unit of the first machining unit, and the adsorption unit of the first machining unit A second cleaning step of removing the semiconductor wafer and cleaning the back surface of the semiconductor wafer with a liquid; and polishing the semiconductor wafer by adsorbing the back surface of the semiconductor wafer to an adsorption portion of a second machining unit. A cleaning step, wherein after the semiconductor wafer is removed from the suction portion of the first machining portion, a predetermined gap is formed between the cleaning step and the suction portion of the first machining portion. Forming and discharging the liquid from the suction portion of the first machining portion to clean the back surface of the semiconductor wafer, and removing the semiconductor wafer from the suction portion of the first machining portion After At least one of the steps of forming a predetermined gap with the suction portion of the machining portion and cleaning the back surface of the semiconductor wafer by discharging liquid from the suction portion of the second machining portion A method for manufacturing a semiconductor device or a semiconductor wafer is provided.

According to the present invention, the cleaning step of cleaning the back surface of the semiconductor wafer with the liquid includes a step of cleaning the back surface of the semiconductor wafer by discharging the liquid from the adsorption unit of the first machining unit, and the second machining process. At least one of the steps of cleaning the back surface of the semiconductor wafer by discharging the liquid from the suction portion of the portion.
In the present invention, since the back surface of the semiconductor wafer is cleaned by discharging the liquid from the adsorption portion, it is not necessary to immerse the semiconductor wafer in the water tank as in the conventional case. Therefore, if the manufacturing method of this invention is used, a water tank will become unnecessary and it will become possible to prevent the enlargement of an apparatus.
Furthermore, in the present invention, since the back surface of the semiconductor wafer is cleaned by discharging the liquid from the suction portion, and the semiconductor wafer is not sucked to the suction portion, cleaning is reliably performed. Can be removed.
Note that the liquid may be discharged from the suction portion of the second machining section for the first time in the cleaning process, and in order to prevent drying of the suction portion of the second machining section, from the previous stage of the cleaning process. Liquid may be constantly discharged throughout the cleaning process.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor wafer which does not invite the enlargement of an apparatus and can remove reliably the slurry adhering to the semiconductor wafer back surface is provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a polishing apparatus 1. The polishing apparatus 1 is an apparatus that polishes (machines) the outer peripheral portion of the semiconductor wafer W. Here, although not shown, the semiconductor wafer W includes a substrate body such as a Si substrate and a plurality of semiconductor layers, insulating layers, and wiring layers stacked on the surface of the substrate body. For example, a transistor or the like is formed by a plurality of semiconductor layers, insulating layers, and wiring layers.
In such a semiconductor wafer W, when a large number of semiconductor layers, insulating layers, wiring layers, and the like are formed on the substrate body, the semiconductor layers, insulating layers, and wiring layers are easily peeled off from the outer periphery of the semiconductor wafer W. If the peeled portion adheres to the surface of the semiconductor wafer W, the device performance may be degraded. Therefore, the chamfering polishing of the semiconductor wafer W having the semiconductor layer, the insulating layer, and the wiring layer formed on the substrate body is performed, and the peeling of the semiconductor layer, the insulating layer, the wiring layer, and the like from the outer peripheral portion of the semiconductor wafer W is prevented. is there.

  The polishing apparatus 1 includes a mounting unit 11 that mounts a cassette that stores a semiconductor wafer W, an alignment unit 12 that aligns the semiconductor wafer W, and first to third polishing units that polish the semiconductor wafer W. Polishing units (machining units) 13 to 15, a first transfer device 16 that transfers the semiconductor wafer W between the mounting unit 11 and the alignment unit 12, the first polishing unit 13, and the third polishing unit A second transfer device 17 for transferring the semiconductor wafer W between the portions 15, a pair of reversing portions 18 for reversing the front and back of the semiconductor wafer W, a fourth polishing portion 19 disposed between the reversing portions 18, and a polishing And a post-processing unit 20 that performs post-processing.

The placement unit 11 is a table on which a plurality of cassettes S containing semiconductor wafers W are arranged in parallel.
The semiconductor wafers W stored in the cassette S are transferred to the alignment unit 12 by the first transfer device 16. Here, the first transport device 16 includes a rail portion 161 extending in parallel with the arrangement direction of the cassettes S, and an arm 162 that moves on the rail portion 161. At the tip of the arm 162, an adsorption part 162A that adsorbs to the back surface of the semiconductor wafer W is provided. The adsorption part 162A adsorbs the back surface of the semiconductor wafer W and carries it.

The alignment unit 12 is disposed adjacent to the placement unit 11 with the first transfer device 16 interposed therebetween.
The alignment unit 12 includes a mounting table 121. Around the mounting table 121, a plurality of alignment pins 122 protruding in the direction perpendicular to the drawing in FIG. The alignment pins 122 are brought into contact with the outer peripheral portion of the semiconductor wafer W, whereby the semiconductor wafer W is centered.

The first polishing unit 13 is disposed adjacent to the alignment unit 12. The first polishing unit 13 includes a suction unit 21 on which the semiconductor wafer W is placed and sucks the back surface of the semiconductor wafer W, and a polishing unit main body 22 (FIG. 8) that polishes the notch of the semiconductor wafer W.
Here, the notch WN of the semiconductor wafer W is a V-shaped notch formed in the outer periphery of the semiconductor wafer (see FIG. 8A). This notch is provided to facilitate alignment of the semiconductor wafer W.
As illustrated in FIG. 2, the suction unit 21 includes a lower chuck 211 that holds the back surface of the semiconductor wafer W, a suction pad 212, a rotating shaft 213, a bearing 214, and a case 215.
The lower chuck 211 is formed in a disk shape, and one through hole 211A is formed at the center. As shown in FIG. 3, a plurality of groove portions 211 </ b> B extending radially from the through hole 211 </ b> A are formed on the surface of the lower chuck 211. The groove 211B communicates with the through hole 211A.
The diameter of the through hole 211A is, for example, 3 to 15 mm. Especially, it is preferable that it is 6-10 mm.

A suction pad 212 is attached on the surface of the lower chuck 211.
As shown in FIG. 3, a through hole 212 </ b> A is formed in the center of the suction pad 212. Furthermore, a plurality of arc-shaped grooves 212B are formed on the surface of the suction pad 212 so as to surround the through hole 212A.
The diameter of the through hole 212A is equal to the through hole 211A of the lower chuck 211, and is, for example, 3 to 15 mm. Especially, it is preferable that it is 6-10 mm.

The rotating shaft 213 includes a main shaft 213A that is inserted into the through hole 211A of the lower chuck 211, and a flange portion 213B that is formed on the main shaft 213A and supports the back surface of the lower chuck 211.
The distal end portion of the main shaft 213A is inserted into the through hole 211A of the lower chuck 211. The main shaft 213A is formed with a through hole 213C extending in the longitudinal direction (axial direction).
Although not shown, a pipe for introducing water into the through hole 213C is connected to the lower end of the main shaft 213A, and a vacuum pump for sucking air in the through hole 213C is also connected. By sucking air in the through-hole 213 </ b> C with a vacuum pump, the back surface of the semiconductor wafer W is sucked and fixed to the suction pad 212.
Further, by introducing water into the through hole 213C, water is discharged through the through hole 213C, the through hole 211A of the lower chuck 211, and the through hole 212A of the suction pad 212.
In other words, water is discharged from the substantially central position of the suction surface of the semiconductor wafer W of the suction portion 21.
Further, the main shaft 213A is configured to be rotatable about the longitudinal direction of the main shaft 213A as a rotation axis, and a ball serving as a bearing is provided between the rotation shaft 213 and a member in the case 215 that houses the rotation shaft 213. A bearing 214 is disposed.

Again, the 2nd grinding | polishing part 14 is demonstrated with reference to FIG.
The second polishing unit 14 is disposed adjacent to the first polishing unit 13 and polishes the outer surface W1 (see FIG. 6) of the semiconductor wafer W. The second polishing unit 14 includes an adsorption unit 21 similar to the first polishing unit 13 and a polishing unit main body 22 (see FIG. 4C) that polishes the outer surface W1 of the semiconductor wafer W.
The polishing unit main body 22 is disposed above the suction unit 21 and is configured to be movable up and down. As shown in FIG. 4C, the polishing section main body 22 has a polishing cloth (not shown) attached to the inside of a cylindrical member 221.
When polishing the outer surface W1 of the semiconductor wafer W, the outer surface W1 of the semiconductor wafer W is brought into contact with a polishing cloth attached to the cylindrical member 221. Then, the suction unit 21 is rotated to rotate the semiconductor wafer W, and the cylindrical member 221 is rotationally driven in a direction opposite to the rotation direction of the semiconductor wafer W.

The third polishing unit 15 is disposed adjacent to the second polishing unit 14. The third polishing portion 15 performs chamfering polishing of the corner portion on the surface side of the outer peripheral portion of the semiconductor wafer W to form a chamfered surface W2 shown in FIG. The third polishing unit 15 includes an adsorption unit 21 and a polishing unit body 23 that performs chamfering polishing of the semiconductor wafer W (see FIG. 5).
The polishing unit main body 23 is disposed above the adsorption unit 21 and is configured to be movable up and down. As shown in FIG. 5, the polishing section main body 23 has a bell-shaped member 231, and a polishing cloth (not shown) is attached to the inside of the bell-shaped member 231.
When chamfering the corners on the surface side of the outer periphery of the semiconductor wafer W, the corners on the surface side of the outer periphery of the semiconductor wafer W are brought into contact with the polishing cloth inside the bell-shaped member 231. Then, the suction portion 21 is rotationally driven to rotate the semiconductor wafer W, and the bell-shaped member 231 is rotationally driven in a direction opposite to the rotational direction of the semiconductor wafer W.

As shown in FIG. 1, the second transfer device 17 transfers the semiconductor wafer W between the first polishing unit 13, the second polishing unit 14, and the third polishing unit 15.
The second transfer device 17 includes a rail portion 171 extending along the arrangement direction of the polishing portions 13 to 15 and a plurality of wafer holding portions (holding portions) 172 that slide on the rail portion 171.
Among the plurality of wafer holding units 172, the first wafer holding unit 172A moves between the alignment unit 12 and the first polishing unit 13, and the semiconductor wafer W is transferred from the alignment unit 12 to the first polishing unit 13. Transport.
The second wafer holding unit 172B moves between the first polishing unit 13 and the second polishing unit 14, and transports the semiconductor wafer W from the first polishing unit 13 to the second polishing unit 14.
The third wafer holding unit 172C moves between the second polishing unit 14 and the third polishing unit 15, and transports the semiconductor wafer W from the second polishing unit 14 to the third polishing unit 15.

Such a wafer holding part 172 includes a sliding part 173 that slides on the rail part 171, and a holding part main body 174 that is fixed to the sliding part 173 and holds the outer peripheral part of the semiconductor wafer W.
As shown in FIG. 2, the holding portion main body 174 is provided at an arm 174C extending from the sliding portion 173, a long frame portion 174A attached to the tip of the arm 174C, and both ends of the frame portion 174A. And a wafer outer periphery holding portion 174B protruding downward.
Although not shown, the arm 174C is movable in the vertical direction on the sliding portion 173.
The frame portion 174A is plate-shaped and has a plurality of holes 174A1. The plurality of holes 174A1 are arranged along the longitudinal direction of the frame portion 174A.
Wafer outer periphery holding portion 174B is a pair of substantially cylindrical protrusions protruding downward from both ends of frame portion 174A, and grooves 174B1 are formed on the outer peripheral surface of the protrusions. By inserting the outer peripheral part of the semiconductor wafer W into the groove 174B1, the semiconductor wafer W is held by the holding part main body 174.

As shown in FIG. 1, the reversing unit 18 is disposed adjacent to the third polishing unit 15 and reverses the front and back of the held semiconductor wafer W.
The reversing unit 18 includes a holding unit main body 174 and a driving unit 181 that rotationally drives the holding unit main body 174. The holding part main body 174 is reversed with the axis along the longitudinal direction of the frame part 174A as a rotation axis.

  The fourth polishing unit 19 includes an adsorption unit 21 similar to the third polishing unit 15 and a polishing unit main body (not shown) similar to the third polishing unit 15. The fourth polishing section 19 performs chamfering polishing at the corner on the back surface side of the wafer (forms a chamfered surface W3 in FIG. 6).

The post-processing unit 20 includes two brush cleaning units 201 that perform cleaning with a roll brush, and a spin cleaning unit 202 that performs spin cleaning.
The two brush cleaning units 201 perform brush cleaning of the semiconductor wafer W while supplying a low-concentration ammonia solution.

Next, a manufacturing process of the semiconductor wafer W using such a polishing apparatus 1 will be described.
This will be described with reference to FIGS. 1, 4, and 5.
First, the semiconductor wafer W is taken out from the cassette S by the first transfer device 16. At this time, the back surface of the semiconductor wafer W is sucked by the suction portion 162A at the tip of the arm 162 of the first transfer device 16, and the semiconductor wafer W is held by the first transfer device 16.
Next, the arm 162 of the first transfer device 16 moves on the rail portion 161 and transfers the semiconductor wafer W to the alignment unit 12.

In the alignment unit 12, the semiconductor wafer W is mounted on the mounting table 121, and centering by the alignment pins 122 is performed.
Thereafter, the wafer holding unit 172 (here, the first wafer holding unit 172A) of the second transfer device 17 is driven, and the first wafer holding unit 172A is moved toward the alignment unit 12 side. The outer peripheral portion of the semiconductor wafer W is inserted into the groove 174B1 of the wafer outer peripheral holding portion 174B of one wafer holding portion 172A. As a result, the semiconductor wafer W is held by the second transfer device 17.

Next, the arm 174 </ b> C of the first wafer holding unit 172 </ b> A is driven to move the semiconductor wafer W above the mounting table 121, and further from the alignment unit 12 toward the first polishing unit 13. The wafer holding portion 172A is moved on the rail portion 171.
When the semiconductor wafer W is transported from the alignment unit 12 toward the first polishing unit 13, water is sprayed from the upper side of the semiconductor wafer W toward the surface side of the semiconductor wafer W. The sprayed water wets the surface of the semiconductor wafer W through the hole 174A1 of the frame part 174A of the first wafer holding part 172A.
In addition, when the semiconductor wafer W is transported from the alignment unit 12 toward the first polishing unit 13, water is sprayed from the lower side of the semiconductor wafer W toward the back side of the semiconductor wafer W. This water wets the back surface of the semiconductor wafer W.
The spraying of water on the semiconductor wafer W is not only performed when the semiconductor wafer W is transported from the alignment unit 12 toward the first polishing unit 13 but also from the first polishing unit 13 to the second polishing unit 14. When transporting from the second polishing section 14 to the third polishing section 15, transporting from the third polishing section 15 to the reversing section 18, transporting from the reversing section 18 to the fourth polishing section 19 In this case, it is also carried out when transporting from the fourth polishing unit 19 to the reversing unit 18 and transporting from the reversing unit 18 to the brush cleaning unit 201. However, this water spray hardly removes the slurry or the like adhering to the back surface of the semiconductor wafer W.

Here, while the semiconductor wafer W is transported from the alignment unit 12 toward the first polishing unit 13, water is discharged upward from the suction unit 21 of the first polishing unit 13. . This water prevents the suction pad 212 of the suction part 21 from being dried.
When the semiconductor wafer W is disposed above the suction unit 21 of the first polishing unit 13, water discharge from the suction unit 21 is stopped.
Thereafter, the arm 174C of the first wafer holding unit 172A is driven downward to place the semiconductor wafer W on the suction unit 21. After the semiconductor wafer W is placed on the adsorption unit 21, the holding of the semiconductor wafer W by the first wafer holding unit 172A is released, and the first wafer holding unit 172A is driven toward the alignment unit 12 side. .
In the suction part 21, air is sucked from the through-hole 213C of the main shaft 213A, and the back surface of the semiconductor wafer W is sucked and fixed to the suction part 21 (see FIG. 4A).
And the notch of the semiconductor wafer W is grind | polished by the grinding | polishing part main body 22 (FIG. 8) of the 1st grinding | polishing part 13 (machining process).
The polishing of the notch of the semiconductor wafer W will be described in detail below with reference to FIG.
8A and 8B are diagrams showing an example of polishing of the notch portion of the semiconductor wafer. FIG. 8A is an image diagram of notch polishing. FIG. 8B is a diagram for explaining the supply of slurry in the notch polishing step. The polishing unit main body 22 includes a polishing drum 811. The suction unit 21 includes a suction stage 812. The semiconductor wafer W is placed on the suction stage 812 and fixed by suction. The notch WN of the wafer W is pressed against the rotating polishing drum 811, the wafer W is tilted up and down, and the slurry is supplied in the direction indicated by the flow path D from the slurry supply nozzle 813, while the notch WN of the semiconductor wafer is formed. Grind.

  Next, the suction fixing of the semiconductor wafer W to the suction unit 21 is released, and the wafer holding unit 172 (here, the second wafer holding unit 172B) of the second transfer device 17 is slid toward the first polishing unit 13 side. The semiconductor wafer W is held by the second wafer holding unit 172B.

The arm 174C of the second wafer holding unit 172B is driven to move the semiconductor wafer W above the suction unit 21 of the first polishing unit 13, and further from the first polishing unit 13 to the second polishing unit 14. The second wafer holding part 172B is moved toward.
At this time, water is discharged upward from the suction portion 21 of the second polishing portion 14. Specifically, water is discharged through the through hole 213 </ b> C of the main shaft 213 </ b> A of the suction portion 21, the through hole 211 </ b> A of the lower chuck 211, and the through hole 212 </ b> A of the suction pad 212. The water discharged from the suction unit 21 prevents the suction pad 212 of the suction unit 21 from being dried.
In addition, while the second wafer holding unit 172B is moved on the rail unit 171 from the first polishing unit 13 toward the second polishing unit 14, the suction unit 21 of the second polishing unit 14 rotates. Driving.

The semiconductor wafer W is positioned above the suction part 21 of the second polishing part 14. When the semiconductor wafer W is disposed above the suction unit 21 of the second polishing unit 14, the suction unit 21 of the second polishing unit 14 stops rotating.
Next, the arm 174C of the second wafer holding unit 172B is driven to bring the semiconductor wafer W closer to the suction unit 21.
Here, the semiconductor wafer W is arranged at a predetermined interval with respect to the suction portion 21. Thereby, water will be discharged from the adsorption | suction part 21 toward the approximate center of the back surface of the semiconductor wafer W. The discharged water flows from the approximate center of the back surface of the semiconductor wafer W toward the outer periphery along the back surface of the semiconductor wafer W, and the back surface of the semiconductor wafer W is cleaned (see FIG. 4B). Washing step). Thereby, the semiconductor wafer W is cleaned in a state where the outer peripheral portion is held by the second wafer holding portion 172B, and the polishing dust and slurry adsorbed on the back surface of the semiconductor wafer W are removed.

Here, the distance between the back surface of the semiconductor wafer W and the adsorbing part 21 for discharging water is 0.5 mm or more and 5 mm or less, and the water pressure of water discharged from the adsorbing part 21 is 0.05 MPa or more, 0. The pressure is preferably 5 MPa or less. Especially, it is preferable that it is 0.1 MPa or more and 0.2 MPa or less.
Moreover, it is preferable that the water discharged from the adsorption | suction part 21 is a pure water. Further, the water discharged from the adsorbing unit 21 may be ultrasonic water.
In this embodiment, while the semiconductor wafer W is being transferred from the first polishing unit 13 toward the second polishing unit 14 and during the cleaning of the back surface of the semiconductor wafer W, the second polishing unit is always performed. Water is discharged from the 14 adsorbing portions 21. Here, while transporting the semiconductor wafer W from the first polishing unit 13 toward the second polishing unit 14, the water pressure discharged from the adsorption unit 21 of the second polishing unit 14, and the semiconductor wafer The water pressure discharged from the adsorbing portion 21 of the second polishing portion 14 when cleaning the back surface of W may be the same or different. For example, after the semiconductor wafer W is arranged at a predetermined interval with respect to the suction part 21 of the second polishing part 14, the water pressure of the water from the suction part 21 is adjusted to 0.05 MPa or more and 0.5 MPa or less. The back surface of the semiconductor wafer W may be cleaned.

When the cleaning of the back surface of the semiconductor wafer W is completed, the water discharge from the suction unit 21 is stopped. The arm 174C of the second wafer holding unit 172B is driven downward to place the semiconductor wafer W on the suction unit 21. After the semiconductor wafer W is placed on the suction unit 21, the holding of the semiconductor wafer W by the second wafer holding unit 172B is released, and the second wafer holding unit 172B is driven toward the first polishing unit 13. The Air is sucked from the through-hole 213 </ b> C of the main shaft 213 </ b> A of the suction part 21, and the semiconductor wafer W is sucked and fixed to the suction part 21.
Thereafter, the polishing unit main body 22 positioned above the suction unit 21 is lowered to bring the outer peripheral surface of the semiconductor wafer W into contact with the polishing cloth. Then, the suction unit 21 is rotationally driven to rotate the semiconductor wafer W, and the polishing unit main body 22 is rotationally driven in a direction opposite to the rotational direction of the semiconductor wafer W, so that the outer peripheral portion (outer surface W1) of the semiconductor wafer W is Is polished (see FIG. 4C, machining step).
The polishing of the outer peripheral portion of the semiconductor wafer W will be described in detail below with reference to FIG.
FIG. 9 is a diagram illustrating an example of polishing of the outer peripheral portion W1 of the semiconductor wafer W. The polishing unit main body 22 includes a polishing pad 911. The suction unit 21 includes a suction stage 912. After the semiconductor wafer W cleaned by the second polishing unit 14 is suction-fixed to the suction stage 912, while supplying the slurry from the slurry supply nozzle 913 in the direction indicated by the flow path D, while rotating the semiconductor wafer W, The outer peripheral portion W1 of the semiconductor wafer is polished.

Next, the suction fixing of the semiconductor wafer W to the suction unit 21 of the second polishing unit 14 is released, and the wafer holding unit 172 (here, the third wafer holding unit 172C) of the second transfer device 17 is moved to the second. Then, the semiconductor wafer W is held by the third wafer holding part 172C.
Then, the semiconductor wafer W is transferred from the second polishing unit 14 to the third polishing unit 15.
At this time, water is discharged upward from the suction portion 21 of the third polishing portion 15.
Further, while the wafer holding unit 172 is moved from the second polishing unit 14 toward the third polishing unit 15, the suction unit 21 of the third polishing unit 15 is driven to rotate.
The semiconductor wafer W is arranged above the suction part 21 of the third polishing part 15 by the third wafer holding part 172C. When the semiconductor wafer W is positioned above the suction unit 21 of the third polishing unit 15, the suction unit 21 stops rotating.
Then, the semiconductor wafer W is brought close to the suction part 21 of the third polishing part 15. The semiconductor wafer W is arranged above the suction part 21 of the third polishing part 15 with a predetermined distance from the suction part 21 of the third polishing part 15. Then, similarly to the above-described cleaning process, the back surface of the semiconductor wafer W is cleaned (cleaning process).

When the cleaning of the back surface of the semiconductor wafer W is completed, the water discharge from the suction unit 21 is stopped. The arm 174C is driven downward to place the semiconductor wafer W on the suction unit 21. After the semiconductor wafer W is placed on the suction unit 21, the holding of the semiconductor wafer W by the third wafer holding unit 172C is released, and the third wafer holding unit 172C is driven toward the second polishing unit 14. The Air is sucked from the through-hole 213C of the main shaft 213A of the suction part 21 of the third wafer holding part 172C, and the semiconductor wafer W is sucked and fixed to the suction part 21.
Thereafter, the bell-shaped member 231 of the polishing unit main body 23 located above the suction unit 21 is lowered to bring the outer peripheral surface of the semiconductor wafer W into contact with the polishing cloth. Then, the suction portion 21 is rotationally driven to rotate the semiconductor wafer W, and the bell-shaped member 231 is rotationally driven in a direction opposite to the rotational direction of the semiconductor wafer W to chamfer and polish the semiconductor wafer W (the chamfered surface W2). (See FIG. 5, machining process).
The chamfered surface polishing of the semiconductor wafer W will be described in detail below with reference to FIG.
FIG. 10 is a diagram illustrating an example of chamfering polishing of the semiconductor wafer W. The polishing unit main body 22 includes a polishing drum 921. The suction unit 21 includes a suction stage 922. After the semiconductor wafer W cleaned by the second polishing unit 14 is suction-fixed to the suction stage 922, while supplying the slurry from the slurry supply nozzle 923 in the direction indicated by the flow path D, while rotating the semiconductor wafer W, The chamfered surface W2 of the semiconductor wafer W is polished with the polishing pad 924.

Next, the semiconductor wafer W on the suction unit 21 of the third polishing unit 15 is transferred to one reversing unit 18 by a transfer device (not shown). On the other hand, the reversing unit 18 holds the semiconductor wafer W with the back surface of the semiconductor wafer W facing downward. Thereafter, the front and back of the semiconductor wafer W are reversed so that the back surface of the semiconductor wafer W faces upward.
Thereafter, the semiconductor wafer W is fixed to the suction portion 21 of the fourth polishing portion 19 and polishing is performed. Here, the surface of the semiconductor wafer W is attracted to the attracting part 21. Here, the cleaning of the semiconductor wafer W from which water is discharged from the adsorption unit 21 is not performed.
When the polishing is completed, the semiconductor wafer W is held by the other reversing unit 18 and the front and back surfaces of the semiconductor wafer W are reversed again. As a result, the back surface of the semiconductor wafer W faces downward.

Thereafter, the semiconductor wafer W is transferred to the brush cleaning unit 201 by a transfer device (not shown).
Each brush cleaning unit 201 performs brush cleaning of the semiconductor wafer W, and then transports it to the spin cleaning unit 202. The semiconductor wafer W is subjected to spin cleaning, and the polishing of the outer peripheral portion of the semiconductor wafer W (bevel polishing) is thus completed.

Below, the effect of this embodiment is demonstrated.
Since the back surface of the semiconductor wafer W is washed by discharging water from the suction portion 21, it is not necessary to immerse the semiconductor wafer W in the water tank as in the conventional case. Therefore, if the manufacturing method of the semiconductor wafer W of this embodiment is used, a water tank will become unnecessary and it will become possible to prevent the enlargement of an apparatus.
Further, in the present embodiment, the back surface of the semiconductor wafer W is cleaned by discharging water from the suction unit 21, and cleaning is not performed in a state where the semiconductor wafer W is sucked by the suction unit 21. The slurry adhering to can be removed reliably.
After removing the slurry adhering to the back surface of the semiconductor wafer W, it can be adsorbed and fixed to the adsorbing portion 21 and polished, so that it is possible to prevent the slurry from firmly adhering to the back surface of the semiconductor wafer W.

Here, when the semiconductor wafer is a substrate on which the semiconductor layer, the insulating layer, and the wiring layer are not formed, even if the slurry adhered to the back surface of the semiconductor wafer is firmly fixed, the high-concentration alkali cleaning is performed. , Can be removed.
However, in the case of the semiconductor wafer W having a semiconductor layer, an insulating layer, and a wiring layer formed on the surface as in this embodiment, it is very difficult to perform high-concentration alkali cleaning.
Therefore, as in the present embodiment, water is discharged from the suction unit 21 to clean the back surface of the semiconductor wafer W, and the slurry adhering to the back surface of the semiconductor wafer W is removed and then fixed to the suction unit 21 and polished. It is very useful to process the semiconductor wafer W by the procedure of performing the above.

In this embodiment, since the back surface of the semiconductor wafer W is cleaned immediately before the suction portion 21 sucks the back surface of the semiconductor wafer W, the suction portion 21 sucks the back surface of the semiconductor wafer W in a dry state. Can be prevented.
Furthermore, the water pressure of the water discharged from the adsorption part 21 is set to 0.05 MPa or more and 0.5 MPa or less, and the distance between the back surface of the semiconductor wafer W and the adsorption part 21 for discharging water is 0.5 mm or more and 5 mm or less. Therefore, the slurry adhering to the back surface of the semiconductor wafer W can be reliably removed.
Here, when the water pressure is less than 0.05 MPa, or the distance between the back surface of the semiconductor wafer W and the suction portion 21 that discharges water exceeds 5 mm, the back surface of the semiconductor wafer W should be sufficiently cleaned. It becomes difficult.
Further, when the water pressure exceeds 0.5 MPa or the distance between the back surface of the semiconductor wafer W and the adsorbing portion 21 for discharging water is less than 0.5 mm, water is poured along the back surface of the semiconductor wafer W. It becomes difficult to flow.

Further, in the present embodiment, the suction unit 21 is rotationally driven before the back surface of the semiconductor wafer W is cleaned by discharging water from the suction unit 21.
Thereby, the slurry adhering to the adsorption part 21 can be removed, and the slurry can be prevented from entering between the adsorption part 21 and the back surface of the semiconductor wafer W.

  In the present embodiment, water is discharged from the suction portion 21 toward the substantially center position on the back surface of the semiconductor wafer W, and the water flows from the approximately center position on the back surface of the semiconductor wafer W toward the outer peripheral portion. Slurry and the like adhering to the back surface of W can be efficiently removed toward the outer periphery of the semiconductor wafer W.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, when cleaning the back surface of the semiconductor wafer W, water is discharged from the suction unit 21 while the rotation of the suction unit 21 is stopped to clean the back surface of the semiconductor wafer W. However, the present invention is not limited thereto, and for example, the back surface of the semiconductor wafer W may be cleaned by discharging water from the adsorption unit 21 while rotationally driving the adsorption unit 21. By doing in this way, the slurry adhering to the back surface of the semiconductor wafer W can be removed more reliably.

In the embodiment, the suction unit 21 of the first polishing unit 13 is not rotationally driven before the semiconductor wafer W is suctioned to the suction unit 21 of the first polishing unit 13. The suction unit 21 of the first polishing unit 13 may be rotationally driven before the semiconductor wafer W is suctioned by the 13 suction units 21.
For example, while the semiconductor wafer W is being transferred from the alignment unit 12 toward the first polishing unit 13 (before the semiconductor wafer W is disposed above the suction unit 21 of the first polishing unit 13). Alternatively, the suction part 21 of the first polishing part 13 may be rotationally driven to remove the slurry adhering to the suction part 21 of the first polishing part 13.

Furthermore, in the embodiment, when cleaning the back surface of the semiconductor wafer W, water is discharged from the adsorption unit 21, but the liquid to be discharged is not limited to water. For example, it may be a diluted solution of an acid / alkali chemical solution that does not react with the slurry, or functional water activated by electrolysis or addition of ozone.
In the above embodiment, after the polishing by the first polishing unit 13 is finished, the semiconductor wafer W is disposed above the suction unit 21 of the second polishing unit 14, and the suction unit of the second polishing unit 14. Although water was discharged from 21 to clean the back surface of the semiconductor wafer W, the present invention is not limited to this. For example, after the polishing by the first polishing unit 13 is finished, the semiconductor wafer W is disposed above the suction unit 21 of the first polishing unit 13, and the suction unit 21 of the first polishing unit 13 and the semiconductor wafer are arranged. A back surface of the semiconductor wafer W may be cleaned by forming a predetermined gap with W and discharging water from the suction portion 21 of the first polishing portion 13. You may perform both the washing | cleaning by the adsorption | suction part 21 of the 1st grinding | polishing part 13, and the washing | cleaning by the adsorption | suction part 21 of the 2nd grinding | polishing part 14. Similarly, after the polishing by the second polishing unit 14 is completed, a predetermined gap is formed between the suction unit 21 of the second polishing unit 14 and the semiconductor wafer W, and the second polishing unit 14 The back surface of the semiconductor wafer W may be cleaned by discharging water from the suction unit 21.

The semiconductor wafer W of the embodiment has a substrate main body and a semiconductor layer formed on the surface of the substrate main body. However, the semiconductor wafer is not limited thereto, and the semiconductor wafer is a substrate on which a semiconductor layer or the like is not formed. It may be composed only of the main body.
Furthermore, in the above-described embodiment, the outer peripheral portion of the semiconductor wafer is polished. However, the present invention is not limited to this. For example, the semiconductor wafer may be polished by a CMP method.
For example, the CMP apparatus includes a first polishing unit and a second polishing unit. The first polishing unit includes a polishing unit main body (a disk-shaped polishing surface plate with a polishing pad attached to the surface) for polishing the surface of the semiconductor wafer, and an adsorption unit for adsorbing and holding the back surface of the semiconductor wafer.
The second polishing unit has a polishing surface plate (polishing unit body) on which a polishing pad having a roughness different from that of the polishing pad of the first polishing unit is attached, and an adsorption unit that adsorbs and holds the back surface of the semiconductor wafer. .
By adsorbing the back surface of the semiconductor wafer to the suction part of the first polishing part of the CMP apparatus, the semiconductor wafer held on the suction part from above the polishing surface plate of the first polishing part is brought close to the polishing surface plate, and the semiconductor The surface of the wafer is polished (first machining process).
Next, the semiconductor wafer is separated from the polishing surface plate of the first polishing unit, the semiconductor wafer is detached from the suction unit of the first polishing unit, and the outer peripheral portion of the semiconductor wafer is held by the transfer device. Then, a semiconductor wafer is conveyed below the adsorption | suction part of a 2nd grinding | polishing part, and water is discharged toward the back surface of a semiconductor wafer from the adsorption | suction part of a 2nd grinding | polishing part (cleaning process). Then, the second polishing is performed by adsorbing the back surface of the semiconductor wafer to the adsorption part of the second polishing part (second machining step).
Furthermore, in the said embodiment, although the outer peripheral part of the semiconductor wafer was grind | polished, you may perform the surface grinding of a semiconductor wafer, for example.

Next, examples of the present invention will be described.
(Example)
The semiconductor wafer was chamfered and polished by the same method as in the previous embodiment. However, the suction part is not rotated before the cleaning of the back surface of the semiconductor wafer.
Further, the distance between the suction part and the back surface of the semiconductor wafer in the cleaning process is 2 mm, and the flow rate of water discharged from the suction part is 3 L / min (water pressure 0.1 MPa).
The results are shown in FIG. The back surface of the semiconductor wafer had no suction pad marks, and the number of particles having a diameter of 0.18 μm or more was less than 500 in the entire wafer.
In the example, even if the number of processed semiconductor wafers increased, the number of particles on the back surface of the semiconductor wafer did not increase.

(Comparative example)
A cleaning process for cleaning the back surface of the semiconductor wafer was not performed.
Other conditions are the same as in the example.
The back surface of the semiconductor wafer after the chamfering polishing was marked with a suction pad, and the number of particles having a diameter of 0.18 μm or more was 4000 or more in the whole wafer.
Furthermore, in the comparative example, with an increase in the number of processed semiconductor wafers, the number of particles having a diameter of 0.18 μm or more further increased from 4000 or more.

It is a top view which shows the grinding | polishing apparatus concerning one Embodiment of this invention. It is sectional drawing which shows the adsorption | suction part of a grinding device. It is a top view which shows the suction pad of a suction part. It is a schematic diagram which shows the manufacturing process of the semiconductor wafer W which uses a grinding | polishing apparatus. It is a schematic diagram which shows the manufacturing process of the semiconductor wafer W which uses a grinding | polishing apparatus. It is a figure which shows the outer peripheral part of a semiconductor wafer. It is a figure which shows the result of an Example. It is a figure which shows the process of grind | polishing the notch part of a semiconductor wafer. It is a figure which shows the process of grind | polishing the outer peripheral part of a semiconductor wafer. It is a figure which shows the process of grind | polishing the chamfering surface of a semiconductor wafer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polishing apparatus 11 Mounting part 12 Positioning part 13 1st grinding | polishing part 14 2nd grinding | polishing part 15 3rd grinding | polishing part 16 1st conveying apparatus 17 2nd conveying apparatus 18 Inversion part 19 4th grinding | polishing part 20 Post-processing unit 21 Suction unit 22 Polishing unit main body 23 Polishing unit main body 121 Mounting base 122 Positioning pin 161 Rail unit 162 Arm 162A Suction unit 171 Rail unit 172 Wafer holding unit 172A First wafer holding unit 172B Second wafer holding Part 172C Third wafer holding part 173 Sliding part 174 Holding part main body 174A Frame part 174A1 Hole 174B Wafer outer periphery holding part 174B1 Groove 174C Arm 181 Drive part 201 Brush cleaning part 202 Spin cleaning part 211 Lower chuck 211A Through hole 211B Groove part 212 Suction pad 212A Through hole 212B Groove 213 Rotating shaft 213A Shaft 213B Flange portion 213C Through hole 214 Ball bearing 215 Case 221 Cylindrical member 231 Bell-shaped member 811 Polishing drum 812 Adsorption stage 813 Slurry supply nozzle 911 Adhesion stage 913 Slurry supply nozzle 921 Polishing drum 922 Adsorption stage 923 Slurry Supply nozzle 924 Polishing pad S Cassette D Flow path W Semiconductor wafer W1 Outer surface W2 Chamfered surface W3 Chamfered surface WN Notch

Claims (8)

A first machining step of machining the semiconductor wafer by adsorbing the back surface of the semiconductor wafer to the adsorption portion of the first machining portion;
A cleaning step of removing the semiconductor wafer from the suction portion of the first machining portion and cleaning the back surface of the semiconductor wafer with a liquid;
A second machining step of polishing the semiconductor wafer by adsorbing the back surface of the semiconductor wafer to an adsorption portion of a second machining portion;
In the cleaning step, after removing the semiconductor wafer from the suction portion of the first machining portion, a predetermined gap is formed between the suction portion of the first machining portion and the first machining portion. A step of cleaning the back surface of the semiconductor wafer by discharging liquid from the suction portion of the machining portion; and after removing the semiconductor wafer from the suction portion of the first machining portion, the second machine A predetermined gap is formed between the suction portion of the processing portion and at least one of the steps of cleaning the back surface of the semiconductor wafer by discharging liquid from the suction portion of the second machining portion. A method of manufacturing a semiconductor device or a semiconductor wafer. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 1,
In the cleaning step, the water pressure of the liquid discharged from the adsorption unit is 0.05 MPa or more and 0.5 MPa or less,
The distance between the back surface of the said semiconductor wafer and the said adsorption part which discharges a liquid is 0.5 mm or more and 5 mm or less, The manufacturing method of the semiconductor device or a semiconductor wafer characterized by the above-mentioned. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 1,
In the cleaning step, the liquid is discharged from the suction portion toward a substantially center position on the back surface of the semiconductor wafer, and the liquid flows from a substantially center position on the back surface of the semiconductor wafer toward the outer peripheral portion. Manufacturing method of semiconductor device or semiconductor wafer. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 1,
In the cleaning step, the outer peripheral part of the semiconductor wafer is held by a holding part of a transfer device. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 1,
In the cleaning step, the semiconductor wafer is removed from the suction portion of the first machining portion, a gap is formed between the semiconductor wafer and the suction portion of the second machining portion, and the first A method of manufacturing a semiconductor device or a semiconductor wafer, comprising: a step of cleaning a back surface of the semiconductor wafer by discharging liquid from an adsorption portion of a second machining section. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 5,
A semiconductor device characterized in that the suction portion of the second machining section is rotationally driven before the formation of a predetermined gap between the semiconductor wafer and the suction portion of the second machining section, or A method for manufacturing a semiconductor wafer. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 1,
The method of manufacturing a semiconductor device or a semiconductor wafer, wherein the first machining step and the second machining step are steps of polishing an outer peripheral portion of the semiconductor wafer. In the manufacturing method of the semiconductor device or semiconductor wafer according to claim 7,
The method of manufacturing a semiconductor device or a semiconductor wafer, wherein the semiconductor wafer is obtained by stacking at least one of a semiconductor layer, an insulating layer, and a wiring layer on a substrate body.

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