JP2004296810A - Etching apparatus and method of substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an etching apparatus to surely realize the etching of only the circumferential edge of a semiconductor wafer. <P>SOLUTION: The etching apparatus comprises a holding and driving mechanism 1 to drive a semiconductor wafer to rotate in the circumferential direction by vertically holding the wafer, and an etching vessel 21 to contain etchant and etch the circumferential edge of the semiconductor wafer to be driven to rotate with the holding and driving mechanism by soaking the wafer into the etchant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an etching apparatus and an etching method for etching a peripheral portion of a disk-shaped substrate.
[0002]
[Prior art]
For example, when a circuit pattern is formed on a semiconductor wafer as a substrate, there is a step of forming a laminated film including a plurality of thin films such as a conductive film and an insulating film on the semiconductor wafer. Film formation on a semiconductor wafer is performed by, for example, a CVD apparatus or the like. When a laminated film is formed on a semiconductor wafer, the laminated film may also be formed on the periphery of the semiconductor wafer. FIG. 4A is a cross-sectional view in which a stacked film M composed of a plurality of thin films is formed on the periphery of a semiconductor wafer W.
[0003]
The semiconductor wafer W on which the laminated film M is formed is subjected to a cleaning process by a spin processing device or the like. In this case, if the peripheral portion of the semiconductor wafer is clamped by the spin processing device, the laminated film M on the peripheral portion may be peeled off, and the peeled laminated film M adheres to the semiconductor wafer W or another semiconductor wafer, and becomes contaminated. Cause
[0004]
Therefore, conventionally, if the laminated film M is formed on the semiconductor wafer W, the peripheral portion is etched over a range of 1 to 2 mm as shown by d in FIG. 4B, and the laminated film formed on the peripheral portion is etched. Removal of M has been performed. As a method of etching the peripheral portion of the semiconductor wafer W, a method in which an etchant is sprayed onto the peripheral portion of the semiconductor wafer W by a nozzle has been performed.
[0005]
[Problems to be solved by the invention]
According to the method of performing etching by spraying an etchant to a peripheral portion of a semiconductor wafer by a nozzle, the etchant sprayed to the peripheral portion scatters on the device surface of the semiconductor wafer, and performs unnecessary etching on the device surface. There is a fear.
[0006]
In addition, when the etching liquid is sprayed onto the peripheral portion of the semiconductor wafer by the nozzle, the peripheral portion of the semiconductor wafer is held by a spin processing device, and the semiconductor wafer is rotated. However, in the case where etching is performed while rotating the peripheral portion of the semiconductor wafer with the spin processing apparatus, the retained portion may not be reliably etched.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a substrate etching apparatus and an etching method which can surely etch a peripheral portion of a semiconductor wafer and do not perform unnecessary etching on a device surface.
[0008]
[Means for Solving the Problems]
The present invention provides an etching apparatus for etching a peripheral portion of a disk-shaped substrate,
A holding drive mechanism that holds the substrate substantially vertically and rotationally drives in the circumferential direction;
An etching bath containing an etching solution and being rotated by the holding drive mechanism so that a peripheral portion of the substrate is immersed in the etching solution and etched.
[0009]
It is preferable that a cleaning tank for containing a cleaning liquid and cleaning a peripheral portion of the substrate etched by the etching liquid in the etching tank with the cleaning liquid be provided beside the etching tank.
[0010]
It is preferable that a liquid draining means for removing the cleaning liquid attached to the substrate cleaned by the cleaning liquid in the cleaning tank is provided.
[0011]
It is preferable that the etching bath and the cleaning bath have an upper surface opened and a slit formed in a side wall of the upper end surface of the side wall, into which a peripheral edge portion of the rotatably driven substrate enters.
[0012]
The holding drive mechanism includes a movable body that is driven up and down, a pair of roller mounting plates provided on the movable body so as to be able to contact and separate in a horizontal direction that intersects with the vertical direction, and a vertical mounting direction on the roller mounting plate. It is preferable that the driving roller includes a pair of driving rollers provided at a predetermined interval for engaging and holding the peripheral portion of the substrate, and a driving source for rotating the driving roller in a predetermined direction.
[0013]
The present invention provides an etching method for etching a peripheral portion of a disk-shaped substrate,
A step of rotating the substrate in a circumferential direction while holding the substrate substantially vertically;
A step of immersing a peripheral portion of the substrate driven in rotation in an etchant to perform etching.
[0014]
It is preferable that the peripheral portion of the substrate etched by the etching solution is washed by dipping in a cleaning solution.
[0015]
According to the present invention, since the periphery is immersed in the etchant and etched while rotating the substrate in the circumferential direction, it is possible to prevent the portions other than the periphery from being etched, and furthermore, to reduce the total length of the outer periphery. Can be surely etched.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0017]
FIG. 1 is a schematic configuration diagram of an etching apparatus according to an embodiment of the present invention. The etching apparatus includes a holding and driving mechanism 1 for a semiconductor wafer W as a substrate. The holding drive mechanism 1 has a base plate 2. On the upper surface of the base plate 2, a pair of guide posts 3 having a rectangular cross section are erected at predetermined intervals.
[0018]
A movable body 4 having a rectangular plate shape is provided on the guide column 3 so as to be vertically drivable. In other words, a pair of prism-shaped receiving members 5 are provided at both ends in the width direction of the back surface of the movable body 4 along the vertical direction, and each pair of the receiving members 5 is slidably fitted to the guide column 3. Have been.
[0019]
A female screw body 6 is provided on one side of the movable body 4 in the width direction. A screw shaft 7 is screwed into the female screw body 6. The screw shaft 7 is connected to a rotation shaft 9 of a vertical drive motor 8 provided on the base plate 2. Therefore, when the vertical drive motor 8 operates and the screw shaft 7 is rotationally driven, the movable body 4 is vertically driven in accordance with the rotation direction of the screw shaft 7 and can be positioned at a predetermined height. I have.
[0020]
A pair of roller mounting plates 11 are held at both ends in the width direction of the surface of the movable body 4 so as to be movable in the width direction. That is, a pair of guide rails 12 are provided at predetermined intervals in the vertical direction at both ends in the width direction of the plate surface of the movable body 4. As shown in FIG. 2, a pair of receiving members 13 slidably engaged with the guide rails 12 are provided on the rear surface of the roller mounting plate 11. Thereby, the pair of roller mounting plates 11 can move in the direction of coming and going.
[0021]
Driving rollers 14 are rotatably provided on the upper and lower portions of each roller mounting plate 11, respectively. As shown in FIG. 2, a V-shaped holding groove 14a is formed on the outer peripheral surface of the driving roller 14. At least one of the four drive rollers 14 is rotationally driven by a roller drive motor 15 as a drive source provided on the back surface of the roller mounting plate 11.
[0022]
As shown in FIG. 1, a rod 17 of a cylinder 16 attached to the movable body 4 with its axis substantially horizontal is connected to the pair of roller attachment plates 11. When the rod 17 is driven, the pair of roller mounting plates 11 move along the guide rails 12. That is, the pair of roller mounting plates 11 is driven in the direction of coming and going.
[0023]
Therefore, if the pair of roller mounting plates 11 is driven in the approaching direction, the semiconductor wafer W can be held by the holding grooves 14a of the four drive rollers 14 as shown in FIG.
[0024]
After the semiconductor wafer W is held by the driving roller 14, the roller driving motor 15 is operated to rotate one driving roller 14 clockwise as indicated by an arrow in FIG. Can be rotated clockwise.
[0025]
The lower end of the semiconductor wafer W held by the four driving rollers 14 projects below the lower end of the movable body 4.
[0026]
The lower end of the semiconductor wafer W is sequentially immersed in the etching liquid L1 stored in the etching tank 21 and the pure water L1 stored in the cleaning tank 22 by rotating the semiconductor wafer W in the circumferential direction.
[0027]
The etching tank 21 and the cleaning tank 22 are each formed of a container having a rectangular cross section and an open top, and are arranged side by side on the base plate 2 with one side wall facing away. Slits 21a and 22a that are open at the upper ends are formed on the side walls of the tanks 21 and 22 that face each other.
[0028]
Each of the slits 21a and 22a has a width slightly larger than the thickness of the semiconductor wafer W. After the semiconductor wafer W is held by the four drive rollers 14 as described later, when the movable body 4 is lowered, the lower end of the semiconductor wafer W enters slits 21 a and 22 a between the etching tank 21 and the cleaning tank 22. . The lower position of the semiconductor wafer W is set at a predetermined height at which the outer peripheral surface of the semiconductor wafer W does not hit the lower ends of the slits 21a and 22a.
[0029]
An etching solution supply tank 23 is connected to the etching tank 21 via a pump 24 and a filter 25 by piping. Whereby in the above etching bath 21 the etchant L ₁ from the supply tank 23 is supplied.
[0030]
The etchant L ₁ supplied to the etching tank 21 overflows from the slit 21a, and flows into the overflow container 26 provided in the side wall outer surface. The etching liquid flowing into the overflow container 26 is recovered by a recovery pipe 27 having one end connected to the bottom and the other end connected to the supply tank 23.
[0031]
The height of the liquid level of the etchant L ₁ of the etching bath 21 is defined by the height of the etching bath 21, it is possible to maintain the height by the supply amount of the etchant L ₁ from the pump 24 .
[0032]
A pure water supply pipe 31 is connected to the cleaning tank 22, and pure water L ₂ as a cleaning liquid is supplied to the cleaning tank 22 through the pure water supply pipe 31. Pure water L ₂ supplied to the cleaning tank 22 overflows from the slit 22a formed in the side wall. Pure water L ₂ which overflows, and flows into the overflow container 32 provided on the side wall outer surface, and is discharged by the drain pipe 33.
[0033]
The peripheral portion of the semiconductor wafer W that has entered the slit 22a of the cleaning tank 22 is cleaned with pure water L2. Pure water that has adhered to the peripheral portion of the semiconductor wafer W that has been washed with the pure water is applied to a pair of nozzle bodies 34 (only one is shown) serving as a liquid draining unit that is disposed with its tip directed to the peripheral portions on both sides of the semiconductor wafer W. ) Is removed by a drying gas injected from the above.
[0034]
Next, the action of removing the laminated film M on the peripheral portion of the semiconductor wafer W by etching using the etching apparatus having the above configuration will be described with reference to FIGS. The semiconductor wafer W is supplied to the etching apparatus by the robot hand 35 shown in FIG. The robot hand 35 has a fixed holding section 35a and a movable holding section 35b.
[0035]
As shown in FIG. 3A, the robot hand 35 having the outer peripheral edge of one end and the other end in the radial direction of the semiconductor wafer W sandwiched by the pair of sandwiching portions 35a and 35b is separated by the cylinder 16 in the separating direction. In a substantially vertical state, between the driving rollers 14 of the pair of roller mounting plates 11 driven in the above, the surface holding the semiconductor wafer W is opposed to the plate surface of the movable body 4 and is lowered from above.
[0036]
When the semiconductor wafer W held by the robot hand 35 is lowered to a position facing the driving roller 14, the lowering stops and the pair of roller mounting plates 11 is driven by the cylinder 16 in the approaching direction. Thereby, as shown in FIG. 3B, the semiconductor wafer W is held by the holding grooves 14a on the outer peripheral surfaces of each pair of drive rollers 14.
[0037]
When the semiconductor wafer W is held by the four drive rollers 14, the movable holding portion 35a of the robot hand 35 is driven in the ascending direction as shown in FIG. 3B, and the semiconductor wafer W is held by the pair of holding portions 35a and 35b. The state is released. Next, the robot hand 35 is driven in a direction away from the movable body 4 and then rises.
[0038]
After the robot hand 35 is raised, the vertical drive motor 8 is operated, and the screw shaft 7 is rotated to lower the movable body 4 to a predetermined height position. Thereby, as shown in FIG. 3 (c), a slit 21a for the lower end of the semiconductor wafer W is formed on the side wall of the etching chamber 21 and the cleaning tank 22 enters the 22a, the outer peripheral edge and the etchant L _1, immersed in pure water and _{L 2.}
[0039]
After setting the height of the semiconductor wafer W, the roller drive motor 15 is operated, and the motor 15 drives one of the four drive rollers 14 to rotate clockwise as indicated by arrows in FIG. As a result, the semiconductor wafer W whose outer peripheral edge is held by the four drive rollers 14 is driven to rotate counterclockwise.
[0040]
Semiconductor wafer W of the slit 21a of each tank 21 and 22, the lower end having entered the 22a is immersed in the etchant _{L 1} and pure water _{L 2.} Therefore, when rotating the semiconductor wafer W, after the outer peripheral edge of the semiconductor wafer W is etched by an etchant etching bath 21, since will be cleaned by the pure water L ₂ of the cleaning tank 22, the semiconductor wafer W Is rotated a plurality of times, as shown in FIG. 4 (b), the excess laminated film M on the peripheral edge can be removed.
[0041]
The etchant _{L 1} and pure water _{L 2} to be supplied to the etching chamber 21 and the cleaning tank 22 overflows from the slit 21a, 22a of each vessel 21, 22. However, by controlling the supply amounts of the etching solution L ₁ and the pure water L ₂ , the liquid level of the etching solution and the pure water defined by the height of the etching bath 21 and the cleaning bath 22 can be adjusted to each slit 21 a. , 22a.
[0042]
Therefore, even if slits 21a and 22a are formed in the side walls of the etching tank 21 and the cleaning tank 22, and the peripheral edge of the semiconductor wafer W is inserted into these slits 21a and 22a, the peripheral edge of the semiconductor wafer W is etched with the etching liquid. L ₁ and pure water L ₂ can be surely immersed, and the periphery thereof can be etched and cleaned.
[0043]
The cleaning tank 22 is provided downstream of the etching tank 21 in the rotation direction of the semiconductor wafer W. Therefore, after the peripheral portion of the semiconductor wafer W is etched by an etchant L ₁ in an etching bath 21, it is an etching solution L ₂ which is attached to the semiconductor wafer W is cleaned and removed and washed immediately with pure water L ₂ of the cleaning tank 22 You.
[0044]
Therefore, even if the etching is performed while rotating the semiconductor wafer W, the etching liquid attached to the peripheral portion of the semiconductor wafer W in the etching tank 21 does not flow to the region where the device is formed, so that the device is formed. The portion can be prevented from being damaged by the etching solution.
[0045]
In addition, since the peripheral portion of the semiconductor wafer W can be cleaned continuously with the etching, the working efficiency can be improved.
[0046]
When the lower end of the semiconductor wafer W is cleaned with pure water in the cleaning tank 22 and rises from the liquid level, the pure water attached to that portion is removed by the gas injected from the nozzle body 34. Therefore, the pure water obtained by cleaning the lower end portion of the semiconductor wafer W is prevented from flowing to the plate surface due to the rotation of the semiconductor wafer W, so that it is possible to prevent the pure water from being stained on the plate surface of the semiconductor wafer W.
[0047]
When the semiconductor wafer W is rotated a plurality of times and etching of the periphery is completed, the roller drive motor 15 is stopped to stop the rotation of the semiconductor wafer W. Next, after raising the movable body 4, the robot hand 35 is lowered to a position facing the semiconductor wafer W, and the lower end of the outer peripheral edge of the semiconductor wafer W is engaged with the fixed holding section 35b. The semiconductor wafer W is held by lowering 35a.
[0048]
Next, the pair of roller mounting plates 11 is driven in a direction in which the semiconductor wafer W is held away by the driving roller 14, and the robot hand 35 is lifted up. Can be taken out.
[0049]
The present invention is not limited to the above embodiment. For example, in the above embodiment, only one of the four drive rollers is driven to rotate, but two or more drive rollers are rotated. It may be driven. Further, the number of drive rollers is not limited to four, but may be three or five or more. The point is that the semiconductor wafer is detachably held in a substantially vertical state and can be rotationally driven in the circumferential direction. I just need.
[0050]
An etching tank was provided on the upstream side in the rotation direction of the semiconductor wafer, and a cleaning tank was provided on the downstream side. However, since the semiconductor wafer is rotated and driven in the circumferential direction in a substantially vertical state, the outer edge of the semiconductor wafer is etched at the time of etching. Most of the etchant attached to the surface falls downward. Therefore, even if the semiconductor wafer etched in the etching bath is not cleaned in the cleaning bath, it is possible to suppress the etchant from flowing to the portion of the semiconductor wafer where the devices are formed.
[0051]
【The invention's effect】
As described above, according to the present invention, while rotating the substrate in the circumferential direction, the peripheral portion is immersed in the etching solution to perform the etching. Therefore, it is possible to reliably etch only the peripheral portion of the semiconductor wafer.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an etching apparatus according to an embodiment of the present invention.
FIG. 2 is a side view of the etching apparatus.
FIGS. 3A to 3C are explanatory views showing the order in which a semiconductor wafer is supplied to an etching apparatus and etched.
FIG. 4A is a cross-sectional view of a part of a semiconductor wafer on which a laminated film is formed, and FIG. 4B is a cross-sectional view showing a state where the laminated film on the periphery of the semiconductor wafer is etched.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Holding drive mechanism, 4 ... Movable body, 8 ... Vertical drive motor, 14 ... Drive roller, 15 ... Roller drive motor, 16 ... Cylinder, 21 ... Etching tank, 22 ... Cleaning tank, 21a, 22a ... Slit.

Claims (7)

In an etching apparatus for etching a peripheral portion of a disk-shaped substrate,
A holding drive mechanism that holds the substrate substantially vertically and rotationally drives in the circumferential direction;
An etching tank containing an etching solution and being rotated by the holding drive mechanism so that a peripheral portion of the substrate is immersed in the etching solution and etched. The cleaning tank according to claim 1, wherein a cleaning liquid is contained on a side of the etching tank, and the cleaning liquid is used to wash a peripheral portion of the substrate etched by the etching liquid in the etching tank with the cleaning liquid. Substrate etching equipment. 3. The substrate etching apparatus according to claim 2, further comprising a liquid removing means for removing the cleaning liquid attached to the substrate cleaned by the cleaning liquid in the cleaning tank. The etching bath and the cleaning bath are characterized in that a slit is formed in the upper end surface of the side wall, the upper surface being open and the side wall being provided with a slit into which the peripheral portion of the substrate to be rotated is inserted. The substrate etching apparatus according to claim 2. The holding and driving mechanism includes a movable body that is driven up and down, a pair of roller mounting plates provided on the movable body so as to be able to contact and separate in a horizontal direction that intersects the vertical direction, and a vertically extending direction along the roller mounting plate. 2. The substrate according to claim 1, comprising a pair of drive rollers provided at a predetermined interval for engaging and holding a peripheral portion of the substrate, and a drive source for rotating the drive roller in a predetermined direction. Etching equipment. In an etching method for etching a peripheral portion of a disk-shaped substrate,
A step of rotating the substrate in a circumferential direction while holding the substrate substantially vertically;
Immersing a peripheral portion of the rotationally driven substrate in an etchant to perform etching. 2. The method for etching a substrate according to claim 1, wherein a peripheral portion of the substrate etched by the etching solution is washed by being immersed in a cleaning solution.

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