JP2002151455A - Cleaning apparatus for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spin type cleaning apparatus of a semiconductor wafer for cleaning contamination well even for the wafer with a large diameter without high revolution that disturbs an air or gas flow in the chamber, by feeding a cleaning solution on the whole surface of the wafer uniformly and sufficiently. SOLUTION: In the single-wafer cleaning apparatus for feeding the surface of the wafer on a spin table surrounded with a cleaning chamber, a feeding means of the cleaning solution has a plurality of nozzles for spouting the cleaning solution to the wafer surface, and each nozzle located around the spin table is adjustable in its cleaning-solution spouting direction and its angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cleaning a semiconductor wafer in a semiconductor device manufacturing process, for example, and more particularly to a spin-type cleaning apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a semiconductor wafer is cleaned not only in a final cleaning process but also in each process. Accordingly, the effect of the wafer cleaning efficiency on the operation efficiency of the entire semiconductor device manufacturing process is not small, and a cleaning method and apparatus with high cleaning efficiency are desired.

For example, a batch immersion method in which a plurality of semiconductor wafers are simultaneously immersed in an immersion tank has been adopted.
However, with the recent increase in the diameter of semiconductor wafers, single wafer processing is adopted in each step, and the same applies to the cleaning step. Then, spin cleaning with the highest cleaning efficiency is mentioned as a single wafer type.

The spin cleaning method uses a spin cleaning apparatus that supplies a cleaning liquid such as a chemical solution or a pure water rinsing liquid from a nozzle onto a surface of the wafer while rotating the wafer by a spin table in a cleaning chamber. By moving in the outer peripheral direction along the wafer surface by force, contaminants such as particles and metal on the wafer surface are washed away. According to such a spin cleaning apparatus, the cleaning time is shorter than that of the batch immersion method.

[0005]

In the spin cleaning apparatus as described above, the nozzle for supplying the cleaning liquid is provided at the center position of the turntable on which the wafer is installed, and ejects the cleaning liquid to the center of the rotating wafer. At the same time, the cleaning liquid is supplied to the entire surface of the wafer by rotating (swinging) the tip of the nozzle from the center of the wafer toward the outer periphery. In this case, the supply position of the cleaning liquid moves along the radial direction of the wafer W as indicated by the trajectory indicated by the arrow in the schematic plan view of the wafer in FIG. 3, and the movement along the radial direction and the rotation of the wafer cause the wafer to move. The cleaning liquid is supplied to the entire surface.

[0006] However, such a conventional spin device is used for a semiconductor wafer having a larger diameter, for example, φ40.
When applied to a 0 mm wafer, in the region on the outer peripheral side of R / 2 (R: radius) of the wafer, the time during which the nozzle is aiming at the region is relatively short, so that the area around the cleaning liquid is insufficient and contaminants A problem arises that removal is difficult.

In order to solve this problem and to allow the cleaning liquid to uniformly flow over the entire surface of the wafer including the outer peripheral region, the rotation speed of the wafer must be increased. However, in the case of a large-diameter wafer having a diameter of 400 mm, a wafer having a diameter of 200 mm is required. The outer peripheral speed is twice as high as that of the above, and if this is further rotated at a higher speed, the outer peripheral speed becomes so high that the airflow in the chamber is greatly disturbed, and the particles and mist are wound up and adhere to the wafer surface. Will be exerted.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to uniformly clean a semiconductor wafer with a cleaning liquid over the entire wafer surface without performing high-speed rotation that disturbs the air flow in a chamber even in the case of spin cleaning of a semiconductor wafer. It is an object of the present invention to provide a cleaning apparatus which can be sufficiently rotated to remove contaminants satisfactorily.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor wafer cleaning apparatus, comprising: a spin table; and a cleaning liquid supply for supplying a cleaning liquid to a surface of the wafer on the spin table. Means, in a single wafer type semiconductor wafer cleaning apparatus comprising a cleaning chamber surrounding the periphery of the spin table, the cleaning liquid supply means,
The apparatus includes a plurality of nozzles for discharging the cleaning liquid toward the wafer surface, and each of the nozzles is disposed around the spin table so as to be able to change and adjust the cleaning liquid discharge direction and angle.

According to a second aspect of the present invention, there is provided a cleaning apparatus for a semiconductor wafer according to the first aspect, wherein each of the nozzles is arranged in a radial direction of a wafer surface on the spin table. The cleaning liquid ejection direction and the angle are selectively adjusted so as to selectively aim at one of a plurality of different parts set in advance.

Further, in the semiconductor wafer cleaning apparatus according to the present invention, in the semiconductor wafer cleaning apparatus according to the second aspect of the present invention, the number of nozzles aimed at different portions in the radial direction of the wafer surface is reduced. The number is set to be larger on the outer peripheral side of the wafer than the center of the wafer.

According to a fourth aspect of the present invention, in the cleaning apparatus for a semiconductor wafer according to the first aspect of the present invention, each of the nozzles has a direction in which the cleaning liquid is incident on the wafer surface. The cleaning liquid discharge direction is adjusted to coincide with the cleaning liquid rotation direction on the wafer at the incident position.

According to the present invention, in a spin cleaning apparatus, a plurality of nozzles for discharging a cleaning liquid to a cleaning liquid supply means are provided around a spin table. Moreover, each nozzle is
Since the discharge direction and the angle can be changed and adjusted, the cleaning liquid can be supplied in any direction and angle from the outer peripheral direction to the surface of the wafer in a region facing each nozzle.

Therefore, according to the present invention, the cleaning liquid discharge angles of the respective nozzles can be set to different desired angles, so that the nozzles can be aimed at different portions in the wafer radial direction. That is, the wafer radial direction can be divided into a plurality of regions, and the plurality of nozzles can be assigned to supply the cleaning liquid to each region.

Thus, substantially all the regions in the radial direction of the wafer are aimed at the nozzles for a sufficient time, and the cleaning liquid is uniformly supplied. For example, if a plurality of nozzles are distributed so as to aim at the vicinity of the center, the vicinity of the middle, and the vicinity of the outer periphery in the wafer radial direction, respectively, and the cleaning liquid is supplied exclusively to a specific region to each nozzle, the conventional one-nozzle swing As in the case of the supply of the cleaning liquid, there is no area where the supply of the cleaning liquid is insufficient due to the short time aimed at by the nozzle (the area on the outer peripheral side of the wafer), and the sufficient cleaning liquid is circulated evenly over the entire surface of the wafer. Can be.

The setting of the cleaning liquid discharge direction of the nozzle is not limited to one for each different region in the wafer radial direction, but may be a plurality of nozzles. With a configuration in which the sharing is increased, the cleaning liquid is supplied more uniformly as a whole.

According to the cleaning apparatus of the present invention, φ
Even in cleaning a large-diameter wafer having a diameter of 400 mm or more, the cleaning liquid can be supplied to the entire surface of the wafer to remove impurities without rotating the wafer at such a high speed as to disturb the air flow in the cleaning chamber. In addition, since there is no component to be driven above the wafer, such as a swing nozzle of a conventional spin cleaning apparatus, particles generated from the driving unit do not drop, and cleaning accuracy is improved.

Further, in the cleaning apparatus of the present invention, the cleaning water can be made incident on the wafer surface in a desired direction by adjusting the discharge direction of the nozzle, so that it coincides with the rotation direction of the wafer and the cleaning liquid on the wafer at the incident position. By setting the cleaning liquid to enter in the direction of rotation, or by adjusting the angle, flow rate, and flow velocity so that the cleaning liquid is incident opposite to the rotation direction, the generation of splashing and mist of the cleaning liquid is prevented, and the cleaning efficiency is further improved. Can be achieved.

At this time, if the flow velocity of the cleaning liquid at the time of incidence coincides with the flow velocity of the cleaning liquid rotating on the wafer, water splashing can be further suppressed, so that the flow velocity of the cleaning liquid matches the flow velocity of the cleaning liquid on the wafer as much as possible. As described above, it is preferable to adopt a configuration in which the discharge speed of the cleaning liquid at the nozzle can be adjusted and set.

Further, by controlling the angles of the nozzles in an interlocking manner, smooth drainage from the wafer can be performed, and a clean dry surface can be obtained. That is, in the final stage of the cleaning that shifts to the drying step, the nozzles are directed from the center of the wafer to the outer periphery while maintaining a sufficient supply of the cleaning liquid in order from the one aiming at the center side in the wafer radial direction. By gradually changing the flow toward the center, a cleaning water flow is generated from the center to the outer periphery, so that drainage accompanied by discharge of contaminants can be favorably performed from the center of the wafer toward the outer periphery. As a result, there is no residual contaminant due to the return of the wastewater on the wafer surface, and the generation of radial or scattered particles after drying is prevented.

It is preferable that the cleaning chamber in the cleaning apparatus of the present invention has a sealable structure. If it can be sealed, if the drying process is continued after the final rinsing of the wafer in the cleaning chamber, the inside of the chamber can be replaced with an inert gas such as high-purity nitrogen to avoid reattachment of contaminants,
The final finishing of cleaning becomes possible in a clean environment, and a highly clean wafer surface can be obtained.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a semiconductor wafer cleaning apparatus according to one embodiment of the present invention, a spin cleaning apparatus having seven nozzles is shown. The spin cleaning apparatus includes a cleaning chamber 1 having a drain 5 and an exhaust suction drain 6.
A cleaning liquid discharge nozzle 3 is provided around the spin table 2 on the chamber wall so that the direction and angle can be changed and adjusted via an angle adjusting mechanism 4.

In the present embodiment, as shown in the schematic plan view of FIG. 2, the cleaning liquid discharge direction of each nozzle is set at a position near the center of the wafer W along the radial direction of the wafer W placed on the spin table 2. A, middle position B, outside position C
The three different positions were set so that they could be shared and aimed. Specifically, one nozzle 3a aiming at the position A, two nozzles 3b aiming at the position B, and four nozzles 3c aiming at the position C from positions arranged at equal angular intervals are set.

The adjusting mechanism 4 changes and adjusts the direction and angle of discharge of the cleaning liquid from the corresponding nozzle 3 in accordance with a drive command from the control unit 10. The supply of a cleaning liquid such as a chemical solution or pure water to each nozzle is supplied under pressure from a respective supply source (not shown) via a pump device P. The control unit 10 drives the pump device P , The supply of the cleaning liquid is also controlled. Further, the flow rate of the cleaning liquid discharged from each nozzle is determined by the cleaning liquid sending speed (discharge speed) by the pump device P. The discharge speed of the pump device P is changed and adjusted so as to obtain a desired cleaning liquid flow speed. Make it possible. Also,
If the switching of the cleaning liquid from the chemical liquid to the rinsing liquid such as pure water is performed in the pump device P, the nozzle can be shared by different cleaning liquids, so that the device design is simple.

The adjusting mechanism 4 has a structure which can be automatically controlled, for example, XY, Z by a stepping motor.
It is convenient to use a mechanism that drives in the (left / right, up / down) direction. In this case, the driving mechanism is attached to the nozzle 3,
By setting the nozzle tip to move on the assumed XY stage and Z axis in the drive mechanism,
The direction and angle of the nozzle 3 can be adjusted. In the present embodiment, it is assumed that the adjustment mechanism 4 of each nozzle is configured to be capable of automatic control using such a stepping motor, and is driven and controlled by the control unit 10.

The nozzle adjustment mechanism may be manually operated. In this case, for example, a configuration in which the nozzle 3 is rotatably installed on the inner wall of the cleaning chamber and the rotation of the nozzle 3 is operated outside the cleaning chamber 1 is considered. This is achieved by forming a rotating part including a nozzle, for example, a ball-shaped part and a supporting part around it from a member that is chemically inert to each other and has a small surface friction resistance, for example, a fluororesin such as polytetrafluoroethylene. Can be easily configured.

By driving the adjusting mechanism 4 through the control unit 10, the angles of the nozzles (3a, 3b, 3c) are adjusted and positioned so as to discharge the cleaning liquid at a predetermined position on the wafer W. You. At this time, the nozzle direction is set so that the incident direction of the cleaning liquid substantially coincides with the rotation direction of the wafer W at the incident position and the cleaning liquid thereon. Further, such that the flow rate of the cleaning liquid discharged from each nozzle substantially matches the flow rate of the cleaning liquid rotating on the wafer W,
The cleaning liquid discharge speed from the pump device to each nozzle is set. With these settings, the cleaning liquid incident on the wafer surface has a small splash and the generation of mist is suppressed.

In the spin cleaning apparatus described above, φ400
mm wafer was cleaned, and the
The rotation speed of 800 to 1000 rpm was required for rotating the cleaning solution over the entire surface in cleaning the mm wafer, but the cleaning solution could be supplied to the front surface of the wafer at the rotation speed of 500 rpm. In particular, in the area on the outer peripheral side of the wafer where it has conventionally been difficult to supply the cleaning liquid, the cleaning liquid is sufficiently supplied by the four nozzles 3c, and a high cleaning effect is obtained.

In the final stage of the cleaning step, which proceeds to the drying step, the nozzles (3a, 3b, 3c) are controlled by a drive control via the control unit 10 while the nozzles (3a, 3b, 3c) are sequentially rotated so as to rotate. It ended while changing the supply direction. That is, first, the rinsing liquid is caused to flow from the center of the wafer toward the intermediate region in the wafer radial direction by rotating the nozzle 3a aiming at the position A near the center of the wafer in the wafer radial direction. By rotating the nozzle 3b aiming at the upper intermediate position B from the center direction of the wafer to the outer peripheral direction, the rinsing liquid is made to flow further toward the outer peripheral direction of the wafer, and then the nozzle 3c aiming at the upper outer peripheral position C in the wafer radial direction is moved to the wafer. By rotating the rinsing liquid from the center direction to the outer peripheral direction, the rinsing liquid is made to flow toward the outer peripheral direction of the wafer.

By the above series of nozzle operations, a drain flow from the center of the wafer to the outer periphery is generated, and contaminants are satisfactorily discharged together with the drain flow without being left on the wafer surface.
After drying, the generation level of radial or scattered particles could be reduced, and a highly clean surface was obtained.

[0031]

As described above, according to the cleaning apparatus for semiconductor wafers of the present invention, it is difficult to uniformly supply a cleaning liquid in the past, and even for a large-diameter wafer in which cleaning is insufficient. In addition, the cleaning liquid can be sufficiently supplied to the whole without rotating at a high speed enough to disturb the air flow in the chamber, and the cleaning efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a semiconductor wafer cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a supply position of a cleaning liquid in the cleaning apparatus of FIG. 1;

FIG. 3 is a schematic plan view showing a supply position of a cleaning liquid in a conventional spin cleaning apparatus.

[Explanation of symbols]

 1: Cleaning chamber 2: Spin table 3a, 3b, 3c: Nozzle 4: Adjustment mechanism 5: Drainage drain 6: Exhaust suction drain 10: Control unit P: Pump device W: Wafer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masatoshi Gima 555 Nakanoya, Nakanaka, Annaka-shi, Gunma Inside the Super Silicon Laboratories Co., Ltd. (72) Masato Imai Inventor 555 Nakanoya, Annaka-shi, Gunma 1 Super Silicon Laboratories Co., Ltd. (72) Isao Fujita, Inventor 2-1-14 Fuchu-cho, Fuchu-shi, Tokyo Pretec Corporation (72) Kazufumi Hirano 2-1-14 Fuchu-cho, Fuchu-shi, Tokyo In Pretec (72) Inventor Yasuhito Ozaki 2-1-14 Fuchu-cho, Fuchu-shi, Tokyo F-term in Pretec (Reference) 3B201 AA03 AB34 AB42 BB23 BB42 CC01 CD31 CD42 CD43

Claims (4)

[Claims] 1. A single-wafer type semiconductor wafer cleaning apparatus comprising: a spin table; cleaning liquid supply means for supplying a cleaning liquid to a surface of a wafer on the spin table; and a cleaning chamber surrounding a periphery of the spin table. The cleaning liquid supply means includes a plurality of nozzles for discharging the cleaning liquid toward the wafer surface, and each of the nozzles is disposed around the spin table so as to be able to change and adjust the cleaning liquid discharge direction and angle. Cleaning equipment for semiconductor wafers. 2. Each of the nozzles is adjusted to a cleaning liquid discharge direction and an angle for selectively aiming at one of a plurality of different portions set in advance on a radial direction of a wafer surface on the spin table. The cleaning apparatus for a semiconductor wafer according to claim 1, wherein: 3. The semiconductor wafer cleaning apparatus according to claim 2, wherein the number of nozzles aimed at different portions in the radial direction of the wafer surface is set to be larger on the outer peripheral side of the wafer than on the center of the wafer. . 4. The nozzle according to claim 1, wherein the direction of incidence of the cleaning liquid on the surface of the wafer is adjusted to the direction of discharge of the cleaning liquid corresponding to the direction of rotation of the cleaning liquid on the wafer at the incident position. The cleaning device for a semiconductor wafer according to the above.