JPH04181717A - Temperature adjustment unit for semiconductor wafer - Google Patents

Abstract

PURPOSE:To reduce costs by a method wherein a temperature adjustment plate with a recessed part is provided to contact-support a wafer in its circumferential area and to support a proximity gap in the center of the wafer with the result that a temperature adjustment process can be performed in a short time with uniformity maintained and higher quality. CONSTITUTION:A temperature adjustment plate 29 that mounts a semiconductor wafer 3 and heat or cool it is provided with a support section 35 that supports the wafer only with the circumferential area of the semiconductor wafer 3 and a recessed part 36 so that a little gap from the center of the semiconductor wafer 3 is maintained not to contact with it. Therefore, the semiconductor wafer 3 undergoes the proximity method process and the center on the rear side will not be contaminated with heavy metals. Thus, a transfer arm will not be contaminated when the transfer is performed by the transfer arm which is equipped with a supporting member which supports the material by using a center section where is not contaminated in the time of the transfer after the process is terminated. Thus, a highly accurate heat-treatment can be performed with superior efficiency, with cleanness and reduced costs.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a temperature control device for semiconductor wafers.

[Prior Art] Conventionally, in the process of forming patterns on semiconductor wafers in the semiconductor device manufacturing process, adhesion treatment or resist coating has been performed to improve the adhesion between the resist and the wafer before applying resist to the wafer. After exposure and before development, standing wave removal is performed to reduce deformation of the photoresist pattern, or after development, the developer and rinse solution remaining in or on the photoresist film are removed by evaporation. , a post bake is performed to harden the photoresist and strengthen its adhesion to the wafer. To perform these heat treatments, a baking device is used that heats the wafer by placing the wafer on a hot plate made of aluminum or the like with a resistance heating element embedded therein. Usually, after being heated in these baking devices, the wafer is transferred onto a cooling plate with a surface similar to a hot plate made of aluminum, etc., with cooling water etc. circulated inside, and after being cooled, it is lined up. It is transported to the next processing step incorporated in the system and undergoes a series of processing.

When performing a series of processing here, if the wafer comes into contact with an aluminum hot plate or cooling plate, the back side becomes contaminated with heavy metals, and as contaminated wafers are transported one after another, the transport equipment becomes contaminated, and the next wafers will also become contaminated if they come into contact with the contaminated portion. Therefore, as shown in FIG. 7, holes 4 are provided in at least three places in the hot plate or cooling plate 1 so that the small balls 2 slightly protrude from the surface.
The wafer 3 is placed on the small sphere 2, or as shown in FIG. The tip of the support pin 6 for transfer, which relatively moves up and down to place the wafer 3 on the hot plate or cooling plate 1 or lift it and transfer it to the transfer arm, is slightly removed from the surface of the hot plate or cooling plate 1. A proximity-type temperature adjustment device was used in which the wafer 3 is stopped at a protruding position with a small gap and is supported so that the wafer 3 does not come into direct contact with a hot plate or cooling plate to perform heat treatment.

[Problems to be Solved by the Invention] However, in a temperature adjustment device using a proximity type hot plate or cooling plate, it is difficult to process the small balls and the grooves in which the small balls are buried. It was not possible to create a ball of uniform height with high precision. Furthermore, it is very difficult and expensive to stop the support bin at a highly accurate position. If the heights of the small balls and support pins are not precisely uniform, there is a drawback that heating or cooling directly causes temperature unevenness within the plane of the wafer. Further, the proximity structure between the hot plate or cooling plate and the wafer has a gap of 100 to 200 μm, and it was not possible to make them closer to each other due to processing accuracy. However, the narrower the gap, the more uniform the heating or cooling temperature of the wafer can be, and the shorter the processing time.

The present invention has been made to eliminate the above-mentioned drawbacks, and has good processing accuracy, so the proximity structure between the wafer and the hot plate or cooling plate can be narrowed, and therefore, heat treatment can be performed efficiently and with high accuracy. An object of the present invention is to provide a semiconductor wafer temperature adjustment device that is clean and can reduce costs.

[Means for Solving the Problems] In order to achieve the above object, a semiconductor wafer temperature adjustment device of the present invention is provided with a temperature adjustment plate for heating or cooling a semiconductor wafer on which a semiconductor wafer is placed. In the apparatus, the temperature adjustment plate is provided with a support portion that contacts the peripheral edge of the semiconductor wafer and supports the semiconductor wafer, and a predetermined slight gap formed between the support portion that supports the semiconductor wafer and the center portion of the semiconductor wafer. It is equipped with a recessed part.

[Function] On the temperature adjustment plate on which the semiconductor wafer is placed and heated or cooled, the support part that supports the wafer only at the peripheral edge of the semiconductor wafer and the center part of the semiconductor wafer maintain a small gap so that they do not come into contact with each other. A recess is provided so that the Therefore, semiconductor wafers undergo proximity processing, and the center of the backside is not contaminated with heavy metals. If the transport arm is equipped with a support member that supports the material at the uncontaminated center during transport after processing, the transport arm will not be contaminated either. Therefore, the semiconductor wafer can be heat-treated in a clean state. Furthermore, since it is easy to form the recesses in the temperature adjustment plate and can be processed with high precision, the depth of the recesses, that is, the proximity gap between the temperature adjustment plate and the semiconductor wafer, can be made very thin. Therefore, it is possible to perform processing at a uniform temperature in a short time.

[Embodiment] An embodiment in which a semiconductor wafer temperature adjustment apparatus of the present invention is applied to a resist processing apparatus for semiconductor wafer manufacturing will be described with reference to the drawings.

As shown in FIG. 1, the resist processing apparatus S includes a mounting table 8 for a cassette 7 containing a semiconductor wafer 3, and a suction bin set 9 for loading and unloading the semiconductor wafer 3 from the cassette 7.
The wafer receiver includes a carrier station 11 equipped with a transfer table 10, etc., and the wafer receiver of the carrier station 11 includes a transport system 12 for transporting wafers from the transfer table 10, a resist coating device 13, a coating device 14, a coating device 15, etc. A process station 16 is provided.

The mounting table 8 for the cassette 7 of the carrier station 11 is connected to a vertical movement drive mechanism (not shown), and can be moved to a position where the wafers housed in the cassette 7 are carried in by suction tweezers 9. Suction tweezers 9 is X
A contact surface 18 that is connected to a drive mechanism (not shown) capable of rotation in YZ directions and θ and that supports the wafer 3 by contacting the center 17 of the wafer 3 as shown in FIG. 2, and a vacuum (not shown) provided on the contact surface 18. A suction port 19 connected to a pump or the like is provided, and the cassette 7 and the wafer holder are placed between the transfer table 10 and the wafer 3
It is designed to carry out the transportation of The wafer receiver of the carrier station 11 carries the wafer 3 in and out from the transfer table 10, and the transfer system 12 of the process station 16 carries the wafer 3
A transport arm 20. It is composed of a robot 21 that horizontally moves and rotates the transport arm 20, a rail 22 that can transport the robot 21 to each device unit position, and the like. As shown in the front view of FIG. 3 and the cross-sectional view of FIG. 3 is also provided. The mounting body 26 has a length a such that it does not contact the peripheral portion 27 of the wafer 3 but contacts the center portion 17 of the wafer 3 .

As shown in FIG. 5, the Burihake device 14 in which the wafer 3 is transferred by such a transfer system 12 has a resistance heating element 28 embedded therein as a heating means to improve the uniformity of heat on the upper surface. A hot plate 29 is provided, which is a temperature adjustment plate made of aluminum or SUS with a large heat capacity. The hot plate 29 is fixed to a heat insulating plate 30 made of a heat insulating material such as ceramic, and the heat insulating plate 30 is fixed to a vertical drive mechanism 31 such as a bellows pump. The vertical drive mechanism 31 is connected to a vacuum pump (not shown) or the like to suction and fix the wafer 3. For example, three through holes 32 are provided in the hot plate 29, and support pins 33 are inserted into the through holes 32 and fixed to the block 34.

The surface of this hot plate 29 has a peripheral edge 2 of the wafer 3.
The support part 35 that supports the wafer 3 by contacting the wafer 7 and the wafer 3
There is a slight gap d between the center part 17 and the center part 17.

A recess 36 is formed to hold the . The recess 36 can be easily formed by reducing the surface of the hot plate 29, and has a depth of 5.
It can be made to be 0 μm. The depth of the recess 36, that is, the gap d,
In order to shorten processing time and heat while maintaining surface uniformity, the shallower the better, and the better to be at a certain distance from the point of contamination on the back side.

From both of these points of view, 50 μm is the optimal gap.

The support portion 35 that contacts the peripheral edge portion 27 of the wafer 3 may be annular, or may be formed at at least three points.

Similarly, as shown in FIG. 6, in the cooling device 15, a cooling water circulation path 37 serving as a cooling means is buried and connected to a cooling water supply body (not shown), and a cooling plate is a temperature adjusting plate made of aluminum or SUS. 38.

It is fixed to a cooling plate 38 and a fixed plate 39, and a vertical drive mechanism 31 such as a bellows pump is fixed to the fixed plate 39. The vertical drive mechanism 31 is connected to a vacuum pump (not shown) or the like, and is capable of absorbing and fixing the wafer 3. Cooling plate 38
Through-holes 40 are provided at three locations, for example, and support pins 41 are inserted into the through-holes 40 and fixed to the block 42 .

A support portion 43 for placing the wafer 3 in contact with the peripheral edge portion 27 and a recess portion 44 for maintaining a slight gap d from the center portion 17 of the wafer 3 are formed on the surface of the cooling plate 38 . The recess 44 can be easily formed by reducing the surface of the cooling plate 38.
It can be made to a depth of 50 μm. The gap d of 50 μm is an optimal distance that maintains the uniformity of the surface, allows the cooling process to be performed in a short time, and prevents contamination of the back surface of the wafer.

A resist coating method for semiconductor wafers will be explained using the resist processing apparatus configured as described above.

The suction tweezers 9 are moved and inserted into the lowest stage of the cassette 7 set on the mounting table 8 of the carrier station 11. The suction tweezers 9 are moved up a predetermined distance, and the wafer 3
The wafer is placed on the contact surface 18, fixed with the suction port 19, and retreated to carry out the wafer from the cassette 7. Then, the wafer receiver places the wafer 3 on the transfer table 10 by horizontally or rotationally moving. At this time, since the contact surface 18 of the suction tweezers 9 has a radius that contacts the center portion 17 of the wafer 3, it does not contact the peripheral portion 27 of the wafer 3. Thereafter, the transport system 12 of the process station 16 is driven.

The robot 21 moves on the rails 22, the transfer arm 20 rotates, the well holder supports the wafer 13 on the transfer table 10, and the robot 21 moves on the rails 22 again to the position of the pre-bake device 14. Then, the robot and Nodo 21 move the transport arm 20
is conveyed onto the hot plate 29 of the pre-bake device 14. At this time, the hot plate 29 is at the lowest position and the support bin 33 is in a protruding state, so when the wafer 3 is placed on the support pin 33, the hot plate 29 is raised by the vertical drive mechanism 31. The peripheral portion 27 of the wafer 3 is supported by the support portion 35 of the hot plate 29, and the center portion 17 of the wafer 3 is kept at a gap d and does not come into contact with the hot plate 29. Then, it is heated to a desired temperature of about 100° C. for a predetermined period of time, for example, 1 minute. With the conventional gap of 100 μm, after heating for 3 minutes, the hot plate 29 is lowered, and the wafer 3 supported by the support bin 33 is supported by the mounting body 26 of the support member 25 of the transfer arm 20 and moved to the cooling device 15. . At this time, the mounting body 26
supports the center part 17 of the wafer 3, and the hot plate 29
Since it does not contact the peripheral edge 27 of the wafer 3 that has contacted the
There is no chance that the mounting body 26 will be contaminated with heavy metals. For this reason,
The wafers 3 that are sequentially transferred by the transfer arm 20 are free from heavy metal contamination. In the cooling device 15, the wafer is placed on the cooling plate 38 by the same operation as the pre-bake device 15, and cooling water is supplied to the cooling water circulation path 37, and the wafer is cooled to room temperature, for example. Thereafter, it is transported to the resist coating device 13 by the transport arm 20. At this time as well, the mounting body 26 supports the center portion 17 of the wafer 3 and does not contact the peripheral portion 27 that has contacted the cooling plate 38, so that heavy metal contamination is not caused. Thereafter, the wafer 3 is transported to a resist coating device 14, where the resist filled on the surface of the wafer 3 is coated with a spin coater or the like. After coating, the back side is cleaned, and the parts that come in contact with heating and cooling in the previous process are cleaned. After the resist coating process, the wafer receiver in the carrier station 11 is transferred by the transfer system 12 to the transfer stand 10, and unloaded by the suction bin set 9 into the cassette 7 that stores the processed wafers. At this time, the contact surface 18 with the wafer 3 when the suction tweezers 9 supports the wafer 3 is
Since it is smaller than the central portion 17, it does not come into contact with the peripheral portion 27 that was in contact with the temperature adjustment plate, so it is not contaminated with heavy metals.

The above description is an explanation of one embodiment of the semiconductor wafer temperature adjustment device of the present invention, and the present invention is not limited thereto, but can be suitably used in a semiconductor wafer heating or cooling device such as a developing device.

[Effects of the Invention] As is clear from the above description, according to the semiconductor wafer temperature adjustment device of the present invention, the wafer is contacted and supported at its periphery, and the center of the wafer is provided with a recess so as to support the proximity gap. A temperature adjustment plate with a temperature adjustment plate is installed, and during transport, the center of the wafer is supported and transported, rather than the periphery that is in contact with the temperature adjustment plate, so the transport system is not contaminated and is manufactured in a clean state. be able to. Furthermore, since the recesses can be easily and accurately formed in the temperature adjustment plate, the proximity gap can be formed much narrower than in the past. Therefore, the temperature adjustment process can be performed in a short time while maintaining uniformity, and a product of high quality and reduced cost can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment in which the semiconductor urchin/S temperature adjustment device of the present invention is applied to a resist processing device, and FIGS. 2, 3, 4, 5, and 6 are FIG. 1 is a diagram showing the main part of one embodiment, and FIGS. 7 and 8 are diagrams showing a conventional example. 3... Semiconductor wafer 17... Center part 20 of semiconductor wafer...
-Transport arm 25...Support member 27...Semiconductor wafer peripheral edge 28...
・Resistance heating element (heating means) 29... Hot plate 33.41... Support bin 35.43... Support part 36.44... Recessed part 37・・・・・・Cooling water circulation path (cooling means) agent Patent attorney Moritani -Yu Figure 1! Figure 2 @ Figure 3 @ Figure 4

Claims (1)

[Claims] A semiconductor wafer temperature adjustment device including a temperature adjustment plate that heats or cools a semiconductor wafer on which the temperature adjustment plate is placed, wherein the temperature adjustment plate contacts a peripheral edge of the semiconductor wafer and supports the semiconductor wafer; A temperature adjusting device for a semiconductor wafer, comprising: a recess provided with a small predetermined gap formed in the center of the semiconductor wafer.