JP2001007177A - Transfer device for semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely control the timing of cooling work after a heating processing and to secure the uniform characteristic of a semiconductor substrate in the various processing steps of a semiconductor wafer. SOLUTION: An arm mechanism 110 takes out a semiconductor wafer 200 where the processing of a former process is terminated. The semiconductor wafer kept by respective arms 112 and 114 is arranged in the upper face position of a transfer base 100. The semiconductor wafer 200 is kept by three erect pins 140, the respective arms 112 and 114 are extended, the respective erect pins 140 are lowered and the semiconductor wafer is placed on the upper face of a cooling plate 130 and is cooled. Then, the erect pins 140 are raised again, the semiconductor wafer 200 is arranged in the positions of the respective arms 112 and 114. The semiconductor wafer is kept again by the respective arms 112 and 114, and the erect pins 140 are lowered. The semiconductor wafer is transferred to the processing position of the next process and is arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate transfer apparatus for removing a semiconductor substrate from a processing position in a previous process and transferring the semiconductor substrate to a processing position in a next process.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view showing a lithography process of a semiconductor wafer. FIG. 3A shows an outline of the lithography process. After forming a resist film on a semiconductor wafer (semiconductor substrate) in S1, the resist film is exposed through a mask pattern in S2, and the resist pattern is developed in S3. I do. FIG. 3B shows the processing from exposure to development in a little more detail.
Bake before development (PBE; Post Exposure)
(Bake), and after cooling (Cool) in S32, development (Developing) is performed in S33. Thereafter, post bake (Post Bake) is performed in S34. After this post-baking (cooling after the post-baking), the process proceeds to the next step.

FIG. 3C schematically shows the structure of an apparatus for performing the above-described exposure and development. The semiconductor wafer exposed by the exposure device (stepper) 10
The developer is transferred to the developing device 20. The developing device 20 includes one pre-development bake unit 20A, one cooling unit 20B, two development units 20C and 20D, and two post bake units 20A.
E and 20F, and by providing two developing units 20C and 20D and two post-baking units 20E and 20F, the overall processing time is reduced. The semiconductor wafer transferred to the developing device 20 passes through a pre-development bake unit 20A and a cooling unit 20B, and is selectively supplied to two developing units 20C and 20D, where the developing processing is performed in each of the developing units 20C and 20D. Then, they are selectively put into the two post-baking units 20E and 20F, and are transferred to the next process through the post-baking process.

FIG. 4 is a perspective view showing a specific example of a transfer apparatus for transferring a semiconductor wafer to each step in the above-described lithography process of a semiconductor wafer. The transfer device includes a transfer base 30 that is transferred according to a processing position of a semiconductor wafer, and an arm mechanism 32 that holds the semiconductor wafer on the transfer base 30. The arm mechanism 32
It has a pair of upper and lower arm plates 32A and 32B formed in an annular shape corresponding to the outer peripheral shape of the semiconductor wafer, and inserts and locks the outer peripheral portion of the semiconductor wafer between the arm plates 32A and 32B to thereby lock the semiconductor wafer. Is held.

The arm mechanism 32 is supported by a tweezer unit 34. The tweezer unit 34 is provided on the transfer base 30 so as to be slidable in the forward and backward directions of the arm mechanism 32, and controls the drive motor 36 and the like. Accordingly, the arm mechanism 32 slides in the forward and backward directions. At the front end of the transfer base 30, a sensor arm 38 having a sensor for detecting the presence or absence of a semiconductor wafer is provided.

[0006]

By the way, in the above-described semiconductor wafer lithography process, the semiconductor wafer that has been baked by the pre-development bake unit 20A is put into the next cooling unit 20B. In this case, the standby time is affected by, for example, the processing time in the preceding exposure processing and the like and the timing of starting the work, and is different for each semiconductor wafer. For this reason, the timing of cooling for each semiconductor wafer is different, the resist film is left in a heated state, and the reaction at a high temperature progresses, causing variations in the characteristics of each resist pattern, and differences in the width and shape of the pattern. There is a problem that occurs.

[0007] Also, depending on the atmosphere (airflow and temperature) during standby, the cooling state differs for each semiconductor wafer, and the characteristics of each resist pattern vary, and the width and shape of the pattern differ. Occurs. Further, when the system is abnormally stopped during such a standby, and when the semiconductor wafer after the baking process is allowed to cool for a long time,
Variations occur in the characteristics of each resist pattern, resulting in differences in pattern width and shape. Therefore, in order to solve such a problem, it is necessary to cool the semiconductor wafer after the pre-development bake treatment at a uniform timing and to maintain the semiconductor wafer at a constant temperature.

However, in the developing device having the above-described configuration, when the timing of feeding each semiconductor wafer to the cooling unit 20B is to be unified by adjusting the flow (wafer flow) of the semiconductor wafer throughout the entire system. Inevitably, wasted time is generated in the preceding step, so that the entire processing time increases and the production efficiency deteriorates.

The same problem occurs not only in the cooling process after the baking process in the developing device but also in the cooling process after various heating processes.

Accordingly, an object of the present invention is to provide a semiconductor substrate capable of freely controlling the timing of a cooling operation after a heat treatment in various processing steps of the semiconductor substrate and ensuring uniform characteristics of the semiconductor substrate. It is to provide a transfer device.

[0011]

According to the present invention, in order to achieve the above object, a semiconductor substrate is taken out from a processing position in a previous process, held, transferred to a processing position in a next process, and installed in the processing position. In the transfer device, a transfer base that is transferred from a position facing the processing position of the preceding process to a position facing the processing position of the next process, and is arranged on the transfer base, and is controlled to move in a direction of expanding and reducing the distance between each other. A pair of arms for holding the semiconductor substrate, a tweezer unit for supporting each arm and controlling the movement of each arm in the enlargement / reduction direction, and processing the tweezer unit and each arm on the transfer base on the transfer base. A moving mechanism that moves in a direction approaching and separating from the position, and each arm holding the semiconductor substrate is moved from the processing position by the moving mechanism. In a state of being disposed in a retracted position as,
A cooling plate provided at a position located on the lower surface of the semiconductor substrate on the transfer base, the cooling plate controlling the temperature of the semiconductor substrate, and an elevating mechanism for bringing the cooling plate close to the semiconductor substrate. I do.

In the semiconductor substrate transfer apparatus of the present invention, the tweezers unit and each arm on the transfer base are advanced by the moving mechanism with respect to the semiconductor substrate disposed at the processing position in the previous process, and the semiconductor substrate is held by each arm. And remove it from the processing position. Then, each arm and the tweezers unit holding the semiconductor substrate are retracted by the moving mechanism, and the semiconductor substrate is arranged on the transfer base. In this state, the elevating mechanism operates to bring the semiconductor substrate close to the cooling plate to perform cooling. Then, after the semiconductor substrate is cooled by the cooling plate, the elevating mechanism operates again to return the semiconductor substrate to the original holding state by each arm. Thereafter, while transferring the transfer base, the tweezers unit and each arm on the transfer base are advanced by the moving mechanism,
The semiconductor substrate held by each arm is set at a processing position in the next step.

As described above, according to the present invention, the transfer device for transferring the semiconductor substrate from the previous process to the next process is provided with the means for controlling the temperature of the semiconductor substrate. Since the semiconductor substrate can be cooled during the standby time until the semiconductor substrate is put in, the semiconductor substrate is taken out of the previous process regardless of the variation in the standby time when shifting from the previous process to the next process. The timing can be set and started appropriately based on the timing. Therefore, for example, the semiconductor substrate taken out from the previous process does not need to be kept in a heated state for a long time, and uniform characteristics can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a semiconductor substrate transfer device according to the present invention will be described. FIG. 1 is a perspective view showing a configuration of a semiconductor substrate transfer device according to an embodiment of the present invention. The transfer device includes a transfer base 100 that is transferred to a position facing each processing position in the order of processing steps of a semiconductor wafer, and an arm mechanism 110 that holds the semiconductor wafer on the transfer base 100. Arm mechanism 110
Is for holding the semiconductor wafer horizontally with respect to the upper surface of the transfer base 100, and has a pair of arc-shaped arms 112 and 114 corresponding to the outer shape of the semiconductor wafer.

Each of the arms 112 and 114 includes a pair of upper and lower arm plates 112A, 112B, 114A and 114, respectively.
B, and each arm plate 112A, 112B, 114A,
The semiconductor wafer is held by inserting and locking the outer peripheral portion of the semiconductor wafer between 114B. Also,
Each arm 112, 114 has a tweezer unit 120.
This tweezers unit 120 is
The movement of each of the arms 112 and 114 is controlled so as to increase or decrease the distance between the arms.

That is, by reducing the distance between the arms 112 and 114, the arms 112 and 114 are arranged along the outer periphery of the semiconductor wafer, and
The semiconductor wafer is held by inserting the outer peripheral portion of the semiconductor wafer between A, 112B, 114A, and 114B.
Further, by increasing the interval between the arms 112 and 114, the arms 112 and 114 are arranged at positions separated from the semiconductor wafer, so that a cooling operation of the semiconductor wafer described later does not interfere. In the present embodiment, by controlling the interval between the two divided arms 112 and 114 in the expanding / contracting direction, a cooling operation of the semiconductor wafer described later can be smoothly performed.

The tweezers unit 120 is incorporated in a slide guide 100A provided on the transfer base 100, and moves along the slide guide 100A in the direction of movement of the arm mechanism 110 (in the direction of the arrow A, ie, in the processing position). (In the direction away from and approaching). The tweezer unit 120 and the arm mechanism 110 are controlled to move in the forward and backward directions by drive control of a drive motor 122 and the like. That is, with the arm mechanism 110 moved to the forward position, the arms 112 and 114 face the semiconductor wafer disposed at the processing position, and take out the semiconductor wafer from the processing position of the semiconductor wafer in each processing step, or perform each processing step. A semiconductor wafer is set at a processing position. In a state where the arm mechanism 110 holding the semiconductor wafer is moved to the retracted position, the arms 112 and 114 are separated from the processing position to be in a standby state between the respective processing steps. Is what you do.

On the upper surface of the transfer base 100, a cooling plate 130 for cooling the semiconductor wafer and an elevating mechanism for cooling the semiconductor wafer in contact with the cooling plate 130 are provided. Cooling plate 130
Is formed in a disk shape corresponding to the semiconductor wafer,
The arm mechanism 110 holding the semiconductor wafer is disposed at a position corresponding to directly below the semiconductor wafer in a state where the arm mechanism 110 is disposed at the above-described retracted position. Inside the cooling plate 130, a flow passage for flowing cooling water is formed.
A temperature controller (not shown) is provided for controlling the cooling plate 130 to a predetermined temperature by flowing cooling water (or cooling gas or the like) having a predetermined temperature through the flow passage. It should be noted that the cooling plate 130 and the temperature control device having the configuration used in the conventional process can be used.

The elevating mechanism has three upright pins (a plurality of support members) 140 that protrude and descend from the upper surface of the transfer base 100 in the elevating direction. Each upright pin 140
Have the same shape as each other, are arranged at the positions of the vertices of an equilateral triangle, and protrude toward the semiconductor wafer through insertion holes formed in the cooling plate 130.
The lifting and lowering unit provided inside the motor 00 controls the lifting and lowering in synchronization with each other.

In such an elevating mechanism, the three upright pins 140 are raised with respect to the semiconductor wafer held by the above-described arm mechanism 110, and the arm mechanism is moved in such a state that the tips thereof are in contact with the lower surface of the semiconductor wafer. Each arm 11 of 110
2 and 114 are opened to release the semiconductor wafer, thereby holding the semiconductor wafer by the three-point support of each upright pin 140. Next, the upright pins 140 are lowered and immersed in the cooling plate 130, so that the semiconductor wafer is placed on the upper surface of the cooling plate 130. Thereby, the semiconductor wafer is cooled by the cooling plate 130. Thereafter, the upright pins 140 move up again, hold the lower surface of the semiconductor wafer again at the ends thereof, move up, and arrange them at the positions of the arms 112 and 114 of the arm mechanism 110. Here, the arms 112 and 114 are contracted to hold the semiconductor wafer. In this state, each of the upright pins 140 descends and sinks into the cooling plate 130, thereby returning to the original state.

At the front end of the transfer base 100, a sensor arm 150 having a sensor for detecting the presence or absence of a semiconductor wafer is provided.

FIG. 2 is a flow chart showing an operation example until the semiconductor wafer taken out of the processing position of the previous step is set to the processing position of the next step by using the above-described transfer device. First, the semiconductor wafer 200 that has been subjected to the pre-process in FIG. 2A is taken out from the processing position in the pre-process by the arm mechanism 110 in FIG. 2B. This operation is performed by each arm 11 of the arm mechanism 110 as described above.
The semiconductor wafer 200 is sandwiched and held from both sides by advancing and shrinking the 2, 114. Then, the respective arms 112 and 114 of the arm mechanism 110 are retracted, and the semiconductor wafer 200 held by the respective arms 112 and 114 is arranged at the upper surface position of the transfer base 100.

Next, referring to FIG.
2. The semiconductor wafer 200 held by
The upright pins 140 are raised to support the lower surface of the semiconductor wafer 200, and the arms 112 and 114 are expanded to release the semiconductor wafer 200.
0 is held by the three-point support of each upright pin 140. Next, in FIG. 2D, each upright pin 140 is lowered,
The semiconductor wafer 200 is placed on the upper surface of the cooling plate 130 and cooled. Thereafter, in FIG. 2E, the upright pins 140 are raised again, and the semiconductor wafer 200 is arranged at the positions of the arms 112 and 114. Then, FIG. 2 (F)
In step (1), the arms 112 and 114 are contracted to hold the semiconductor wafer 200, the upright pins 140 are lowered, and the semiconductor wafer 200 is transferred and arranged at the processing position of the next step. Thus, the next process is started in FIG.

The pre-process shown in FIG. 2A is, for example, the pre-development baking process described in the above-described conventional example.
The next step shown in (G) is a cooling step. In this way, the cooling can be started at a predetermined timing after the pre-development bake treatment, and the reaction of the resist film due to the high temperature during the standby time to the next process is suppressed, and the uniformity of development is improved. be able to. Further, such a cooling process on the transfer device may be applied when shifting from the cooling process to the developing process. In this way, the cooling state of the semiconductor wafer once cooled can be effectively maintained regardless of the length of the standby time, and the temperature of the wafer (resist film) can be kept constant to improve the uniformity of development. Further, the present invention is not limited to the processing by such a developing device, but can be applied to a semiconductor wafer processing step including various heat treatments.

As described above, the semiconductor wafer transfer device according to the present embodiment has a function of cooling the semiconductor wafer when the semiconductor wafer is transferred from the previous process to the next process. Since the semiconductor wafer can be cooled during the standby time before the wafer is put into the next process, the semiconductor wafer cooling timing can be adjusted regardless of the variation in the standby time for shifting from the previous process to the next process. Cooling can be started by appropriately setting based on the timing taken out of the process.
Therefore, the semiconductor wafer taken out of the previous process is not kept on standby for a long time in a heated state, and uniform characteristics can be obtained.

In the above example, the semiconductor wafer is cooled to a predetermined temperature by the cooling plate.
In addition to the cooling function, a function of detecting the temperature of the semiconductor wafer may be provided, and the temperature of the cooling plate may be controlled based on the detected value. In this case, a detector of a temperature sensor is provided at the tip of the above-described upright pin (support member), and when the upright pin contacts the semiconductor wafer, the temperature is detected in real time, and the cooling operation is controlled based on the detected value. Such a configuration can be adopted.

[0027]

As described above, according to the present invention, a transfer device for transferring a semiconductor substrate from a previous process to a next process is provided.
Means for controlling the temperature of the semiconductor substrate by the cooling plate is provided. For this reason, the temperature of the semiconductor substrate can be controlled during the standby time until the semiconductor substrate is taken out from the previous process and put into the next process, so that the cooling timing of the semiconductor substrate can be changed from the previous process to the next process. Regardless of the variation in time, cooling can be started by appropriately setting the timing based on the timing when the semiconductor substrate is taken out from the previous process.

Therefore, the semiconductor substrate taken out of the previous process is not kept on standby for a long time in a heated state, and uniform characteristics can be obtained. In addition, it is possible to control the characteristics of each semiconductor substrate by adjusting the temperature of the cooling plate appropriately for the atmosphere (airflow and temperature) during standby, and the system stops abnormally during standby. Also in this case, it is possible to suppress the adverse effect of cooling for a long time by proper temperature control by the cooling plate, and to prevent deterioration of characteristics. In addition, it is not necessary to perform flow control such that the standby time of each process is equalized for each semiconductor substrate, and it is possible to improve characteristics without lowering the overall processing efficiency while maintaining productivity. Become.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of a semiconductor wafer transfer device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation example until a semiconductor wafer taken out of a processing position of a previous process is set to a processing position of a next process using the transfer device shown in FIG. 1;

FIG. 3 is an explanatory view showing a lithography step of a semiconductor wafer.

FIG. 4 is a perspective view showing a configuration example of a conventional semiconductor wafer transfer device.

[Explanation of symbols]

100: transfer base, 110: arm mechanism, 11
2, 114 ... arm, 112A, 112B, 114
A, 114B: arm plate, 120: tweezer unit, 122: drive motor, 130: cooling plate, 140: upright pin, 150: sensor arm.

Claims (13)

[Claims] 1. A semiconductor substrate is taken out from a processing position in a previous process and held, and is transferred to a processing position in a next process.
In the transfer device to be installed at the processing position, a transfer base that is transferred from a position facing the processing position of the previous process to a position facing the processing position of the next process, and disposed on the transfer base and spaced apart from each other. The pair of arms holding the semiconductor substrate is controlled by moving in the expanding / contracting direction, a pair of tweezers units that support the respective arms and control the movement of the respective arms in the expanding / contracting direction, A moving mechanism that moves on the transfer base in a direction approaching and separating from the processing position; and a state where each arm holding the semiconductor substrate is disposed at a retracted position away from the processing position by the moving mechanism. A cooling plate provided on a portion of the transfer base located on the lower surface of the semiconductor substrate and controlling a temperature of the semiconductor substrate , The transfer device of the semiconductor substrate and having and a lifting mechanism for close the cooling plate to the semiconductor substrate. 2. The apparatus according to claim 1, wherein the lifting mechanism includes a plurality of supporting members that protrude and descend from an upper surface of the transfer base in an ascending and descending direction, and each of the arms holding the semiconductor substrate is disposed in a retracted position. A member projects from the lower surface of the semiconductor substrate, and each arm receives the semiconductor substrate by each support member in a state where the semiconductor substrate is released, and thereafter, each support member is immersed on the transfer base side, whereby the semiconductor substrate is cooled by the cooling plate. 2. The semiconductor substrate transfer device according to claim 1, wherein a temperature control is performed by being disposed on the semiconductor substrate. 3. After the semiconductor substrate is placed on the cooling plate to perform temperature control, the support members are projected from a transfer base, and the semiconductor substrate is placed at a holding position by the arms. 3. The semiconductor substrate transfer device according to claim 2, wherein the semiconductor substrate is held again by each of the arms. 4. The plurality of support members have the same shape as each other.
3. The semiconductor substrate transfer device according to claim 2, wherein the pin is a pin and protrudes toward the semiconductor substrate through an insertion hole formed in the cooling plate. 5. Each of the arms has a pair of arm plates formed in an arc shape corresponding to an outer peripheral shape of the semiconductor substrate, and sandwiching an outer peripheral portion of the semiconductor substrate in a thickness direction.
By moving each arm in the shrinking direction with respect to each other, the outer peripheral portion of the semiconductor substrate is held between the arm plates to hold the semiconductor substrate, and by moving each arm in the expanding direction with respect to each other, 3. The apparatus for transferring a semiconductor substrate according to claim 2, wherein the arm plate is arranged so as to be completely separated from the semiconductor substrate. 6. The semiconductor substrate transfer device according to claim 1, further comprising temperature control means for controlling said cooling plate to a predetermined temperature. 7. The semiconductor substrate transfer device according to claim 1, wherein said temperature control means is means for flowing cooling water through a flow passage provided in a cooling plate. 8. The semiconductor substrate transfer device according to claim 1, further comprising a detecting unit for detecting a temperature of the semiconductor substrate. 9. The semiconductor substrate transfer device according to claim 2, wherein a detecting means for detecting the temperature of the semiconductor substrate is provided on the support member. 10. The semiconductor substrate transfer apparatus according to claim 1, wherein the temperature control of the semiconductor substrate by the cooling plate is performed during a waiting time between the previous step and the next step. 11. The apparatus according to claim 1, wherein the pre-process includes a heat treatment of the semiconductor substrate. 12. The semiconductor substrate transfer apparatus according to claim 1, wherein said pre-process is a resist film coating process. 13. The apparatus according to claim 1, wherein the pre-process is a development process after exposure of the resist film.