JPH07142339A - Rotation treatment device - Google Patents

Abstract

PURPOSE:To improve throughput in a manufacturing process by always making constant the direction of a substrate to be treated which is placed and fixed to a spin chuck. CONSTITUTION:A control part 36 for making constant a drive signal required for rotating the rotary drive means of a spin chuck 14 and a signal input condition 34 for stopping the rotation of the spin chuck 14 according to the rotary signal for each revolution when a rotary drive means 32 accompanied by treatment end completes rotating regardless of the signal output state for each rotation is provided. Therefore, when stopping the spin chuck 14 according to a rotary signal output for each rotation when the rotation according to the treatment end of the spin chuck 14, the spin chuck 14 can be stopped at a true stop position while error output generated in the transition period of deceleration, etc., and a position deviation due to inertial are prevented, thus indexing the true stop position when carrying out a substrate to be treated of the spin chuck 14 matching the direction when carrying in the substrate to be treated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation processing device,
More specifically, it relates to a drive structure of a spin chuck used in a resist coating apparatus.

[0002]

2. Description of the Related Art Generally, in a semiconductor manufacturing process, a predetermined circuit pattern is transferred onto a substrate to be processed such as a semiconductor wafer or a glass substrate for LCD by using photolithography process. For this, a resist coating device is used as a rotation processing device for coating a photoresist solution, which is a photosensitizer, on a substrate.

In the above coating apparatus, there is provided a spin chuck capable of placing the substrates to be processed contained in the carrier station one by one and fixing and rotating them by vacuum suction. This spin chuck includes a rotary shaft connected to a mounting plate, and the rotary shaft is, for example, a shaft of a servo motor. Therefore, when the substrate to be processed is placed and fixed and the coating process is executed,
The spin chuck can be rotated while the central portion of the substrate to be processed is locked, and the resist liquid is dropped and supplied at the time of rotation.

The rotational drive of the spin chuck is set by sequence control in the semiconductor manufacturing process. That is, when the substrate to be processed transferred from the carrier station by the transfer arm is placed and fixed on the spin chuck, it is rotationally driven within a time corresponding to the coating step. Therefore, the sequence control unit outputs a drive signal for continuing the rotation within the drive time to the servo motor that is the drive source of the spin chuck, and feedback-controls the actual rotation state.
In the feedback control, as an example, a process of correcting the deviation based on the phase signal from the encoder that is set to interlock with the motor is performed.

[0005]

The rotation control of the spin chuck has the following problems.

That is, the substrate to be processed placed and fixed by the spin chuck generally has a notch portion called an orientation flat formed in a part of the peripheral edge thereof, and the notch is used as a reference in each process. The orientation is adjusted. However, the spin chuck does not set the rotation start position based on the orientation of the notch, that is, the position of the notch, and simply rotates based on the processing time in the process that requires rotation. It is supposed to do. For this reason, the arbitrarily set position on the spin chuck does not always coincide with the start of rotation drive and the stop of rotation drive. Therefore, if the position of the spin chuck at the arbitrary position on the spin chuck, in other words, the direction of the spin chuck when this position is used as a reference is different between when the rotation is started and when the rotation is stopped, the mounted and fixed substrate to be processed is The orientation is not the same when loaded into the spin chuck and when loaded out of the spin chuck.

As a result, when the orientation of the substrate to be processed at the time of loading is used as a reference, the alignment between the coating step carried out after the loading and the exposure step carried out after this coating step may not be proper, or Alternatively, there is a risk that interference may occur with the storage portion of the cassette when the cassette is inserted into the cassette at the carrier station. Therefore, conventionally, when the rotation of the spin chuck is stopped, adjustment may be performed to match the orientation of the substrate to be processed at the time of loading. Therefore, if the adjustment amount is large, the adjustment time becomes longer, and the throughput in the manufacturing process may deteriorate.

Therefore, in view of the above problems in the conventional coating apparatus, an object of the present invention is to improve the throughput in the manufacturing process by always keeping the orientation of the substrate to be processed mounted and fixed on the spin chuck constant. It is to provide a rotation processing device capable of performing the above.

[0009]

In order to achieve this object, the invention according to claim 1 is one in which a resist solution is dripped or dropped onto a substrate having a rotation position reference portion fixed on a rotatable mounting table. In a rotation processing device for forming a uniform coating film on a substrate by continuously supplying, a means for rotating the mounting table, a means for outputting a rotation signal for each rotation of the rotation driving means, and the rotation driving. The drive signal necessary for one rotation of the means is output, and the presence or absence of a signal output for each rotation at the time corresponding to the end of rotation of the rotation drive means is detected, and when the signal is output, And a control unit for stopping the rotation driving means.

According to a second aspect of the present invention, in the first aspect, the control unit performs stable rotation at least once at a time corresponding to the end of the rotation of the rotation drive means by a rotation speed lower than the rotation speed at the end of the rotation. It is characterized by continuing.

[0011]

According to the present invention, when the spin chuck rotational drive is stopped at the end of the coating step, the rotation chucking signal is output when the rotation signal for each rotation is not output after the rotation is continued for a plurality of times. The rotation of the rotation driving means is continued until output. Therefore, at the end of the coating process, the rotation of the spin chuck can be stopped by determining the true stop position based on the presence / absence of a signal output for each rotation. Therefore, if the signal output for each rotation is a direction determining signal with reference to an arbitrary point of the spin chuck, it is possible to detect the direction determining signal only when the rotation of the spin chuck is started and stopped. That is, the rotation position reference portion of the substrate to be processed can be always matched at the time of loading and unloading.

[0012]

The present invention will be described in detail below with reference to the illustrated embodiments.

The coating apparatus according to the present invention, particularly the coating apparatus for coating a resist, is incorporated in an apparatus for implementing the substrate processing system shown in FIG.

The configuration for implementing the substrate processing system will be described below with reference to FIG.

In the substrate processing system, the coating pretreatment step,
A coating process, a developing process and a baking process are carried out. Therefore, in FIG. 2, the substrate W to be processed such as a semiconductor wafer is processed.
Are stored in a plurality of cassettes 102 installed in the carrier station 100. Further, the carrier station 100 is provided with an auxiliary arm 106 for carrying in / out and positioning the substrate W at the center thereof and for delivering the substrate W to the main arm 104. In the system shown in FIG. 2, two main arms 104 are provided along the installation direction of each device described later,
These main arms 104 are arranged on a conveyance path parallel to the installation direction of each device, and are movable along the installation direction of each device.

The devices for carrying out the above steps are arranged so as to face each other across the transport path, and each device includes a brush scrubber 108 and a high-pressure jet cleaning device 110 on the side of the carrier station 100.
However, a developing device 112 is arranged on the opposite side of the transfer path of the main arm 104, and a heating device 114 is arranged adjacent to the developing device 112. The brush scrubber 108 and the high-pressure jet cleaning machine 110 are provided to remove particles adhering to the substrate to be processed before the resist coating step, and the substrate to be processed is cleaned with a brush and with high-pressure jet water. It is supposed to do. In addition, the heating device 114 is configured to apply the excess water or the resist solution on the substrate W to be processed after the substrate W to be processed.
It is used for removing the solvent remaining on the upper side, and in the system shown in FIG. 2, two units are stacked corresponding to the number of developing devices 112.

Further, the adhesion device 1 is provided at a position adjacent to the heating device 114 via a connection unit 116.
18 is installed, and a cooling device 120 is arranged below this. The adhesion device 118 is a device for performing a hydrophobic treatment for improving the adhesiveness of the resist on the substrate to be processed, and as an example, the HM in a vapor state is used.
By acting DS (hexamethyldisilazane), the hydroxyl group (--OH) on the substrate to be treated is replaced with a methyl group (CH3). Then, these devices 118, 12
On the side of 0, the heating devices 114 are arranged so that two heating devices 114 are stacked in two rows.

Further, the heating device 114 and the adhesion device 11 are sandwiched across the transfer path of the main arm 104.
A resist coating device 130 is arranged in parallel at a position facing 8 of FIG. Although not shown, an exposure device or the like for exposing a predetermined fine pattern on the resist film is installed at a position adjacent to the resist coating device 130.

On the other hand, the resist coating apparatus 130 has a structure shown in FIG.

That is, there is provided a resist coating unit 10 for coating a resist liquid on a semiconductor wafer which is the substrate W to be processed. The resist coating unit 10 includes a cup 12 having an upper opening, and inside the cup 12, for example, a rotatable and vertically movable spin chuck 14 composed of a vacuum chuck is arranged.
The cup 12 is for receiving the resist solution that is scattered during the resist application and the rinse solution that is scattered during the side rinse. Therefore, the bottom portion is inclined so that the waste solution of the resist solution and the rinse solution can be collected. I am allowed. A waste liquid discharge pipe 16 and an exhaust pipe 18 are connected to the inclined end portion of the bottom portion of the cup 12 so as to discharge the waste liquid and the atmosphere in the cup 12. Regarding the atmosphere, the resist and the gas are separated and discharged through a mist trap (not shown).

Although not shown, a side rinse portion is arranged on the side portion of the cup 12 so that the resist adhering to the peripheral portion of the semiconductor wafer W can be dissolved and removed after the resist application. . Further, on the side portion of the cup 12, at a position facing the side rinse portion with the spin chuck 14 in between, a nozzle standby portion 22 for waiting the liquid supply nozzle 20 for discharging the resist liquid, and a dummy liquid discharge portion for the resist liquid. 24 are arranged respectively. The details of the movement of the liquid supply nozzle 20 with respect to the nozzle standby unit 22 and the dummy discharge unit 24 are not shown, but as an example,
This is performed by a gripping member that is movable in the direction in which the above two parts are arranged in parallel and can move up and down, and can also be moved to the surface of the semiconductor wafer on the spin chuck 14 by this gripping member. In the nozzle standby part 22 and the dummy discharge part 24, as in the prior art, when the coating nozzle is not used, the nozzle is positioned in a standby part having a solvent bath and placed in a solvent or solvent atmosphere, and When the resist solution is applied again, the nozzle is taken out of the solvent bath and the dry resist solution remaining in the nozzle is discarded, that is, so-called dummy dispensing is performed immediately before.

On the other hand, the spin chuck 14 can be linked to the rotation of the servo motor 32 by being connected to the output shaft of the servo motor 32 which constitutes the rotation driving means.

The servomotor 32 is set in a rotating state by an output signal from a rotary encoder 34 which is integrated with a rotary shaft. Therefore, as shown in FIG. 4, the rotary encoder 34 has slits 34A for extracting phase signals, which are formed at equal intervals in the circumferential direction and correspond to one rotation, and have different diameters from the slits 34A. Therefore, the origin position signal slit 34B is formed so that one output pulse can be obtained for all the slits 34A. The phase signal extracting slit 34A has a pulse corresponding to a phase difference signal (U, V, W phase signal) well known in this type of servo mechanism and a pulse corresponding to a rotation direction discrimination signal (A, B phase signal). And the origin position signal slit 34B is a slit for outputting a pulse for each rotation, that is, a so-called slit for outputting a synchronization signal for each rotation. It is used as a signal (Z-phase signal) for stopping at the true stop position. Therefore, the origin position signal slit 34B is formed, for example, with a positional relationship in which one output pulse is obtained when all the pulses are output by the signal extracting slit 34A over time. Then, the signals resulting from the output pulses from the respective slits are output to the control unit 36 and the motor 3
2 rotation control is performed.

That is, in FIG. 1, the control unit 36 is mainly composed of a microcomputer.
As related to this embodiment, the encoder 34 is connected to the input side, and the drive circuit 38 of the servo motor 32 is connected to the output side via an I / O interface (not shown).

The encoder 34 has a structure in which an optical sensor (not shown) detects the phase signal extracting slit 34A and the origin position signal slit 34B formed along the circumferential direction. As shown in FIG. 5, when the number of pulse signals from the signal extracting slits 34A corresponding to one rotation of the motor 32 is output, the origin position signal slits 34
The pulse signal (S1) from B is output. In the case of this embodiment, the number of pulses per rotation is 1000. Therefore, the pulse for the origin position signal is 360 (°)
It is output at a rate of × 1/1000 (pieces).

On the other hand, the control unit 36 executes the rotation control and the direction alignment control of the motor 32 during the coating process. Regarding the rotation control, feedback control based on the rotation command signal of the rotation direction determination (A, B signals) and the rotation speed (U, V, W signals) is performed as in this type of control by the servo mechanism. To be done. Then, the rotation direction alignment control is control for aligning the orientation of the spin chuck 14 at an arbitrary position when the substrate W to be processed is loaded and unloaded.
For this reason, the control unit 36 receives the synchronization signal at the start of the process and at the end of the process, the spin chuck 14
The rotation of the spin chuck 14 is temporarily stopped, and thereafter, the rotation is restarted at a speed lower than the speed in the steady state, and the spin chuck 14 is stopped when a synchronization signal, that is, a so-called origin position signal is input. Note that the speed may be controlled to change from high speed to low speed without temporarily stopping the rotation at the end of the process. Therefore, the spin chuck 14 stopped at the low speed rotation after the processing is accurately set in the same direction as that at the time of starting the processing. In this case, the orientations are made to coincide with each other, for example, by making the positions of the orientation flats corresponding to the rotational position reference portions of the substrate the same. Also,
The control unit 36 prepares for a stop in the case where a synchronization signal is input during low-speed rotation so as to prevent the low-speed rotation of the spin chuck 14 from being stopped in a steady state, that is, during a transitional period such as acceleration / deceleration. The process is executed. That is, for example, when the origin position signal slit 34B in the encoder 34 is stopped at a position before facing the optical sensor at the time of stopping at the end of the process, this process starts rotation from this position, Since it corresponds to acceleration, it cannot be stopped instantaneously due to inertia when a stop command is issued, so it is a position different from that at the start of processing, in other words, the slit 34B for origin position signal at the start of processing and the optical sensor. It is executed in order to prevent the opposite relationship of the above from being broken. Therefore, by executing the rotation at the low speed steady state, it is possible to prevent the unstable state of the stop position in the transition period.

That is, when the motor 32 is stopped at the time when the pulse signal from the Z phase of the rotary encoder 34 is output at the time when the processing of the entire coating process is finished, the rotation start position is temporarily at a position corresponding to the Z phase. If it starts from the spin chuck 14 at the time of rotation stop for carrying out
The direction of can be matched with the start of rotation. However, in reality, when the rotation speed in the coating process is suddenly stopped, the motor is placed at a position corresponding to the output pulse from the Z phase due to the delay of the pulse phase that is likely to occur during the transitional period such as inertia or deceleration. It may not be possible to stop 32. In particular, in the case of a servomotor such as a pulse motor which does not take a form in which the rotation state is set in response to the intermittent excitation state between the magnetic poles, the above phenomenon is remarkable. Therefore, in this embodiment, regardless of the output state of the pulse signal from the Z phase at the end of the coating process, in other words, the origin position signal, the rotation is continued a plurality of times and the low speed rotation is performed in the steady state. The rotation is stopped by the origin position signal of.

The above control is illustrated in FIG. In FIG. 6, (A) is a state when the position of the Z phase is facing the detection sensor at the end of the process, as shown in (C), and (B) and (D) are after the process. The respective states are shown when the Z-phase faces the detection sensor. And (C) and (D) have shown the positional relationship of a Z phase and a detection sensor.

In FIG. 6, when an arbitrary position of the spin chuck 14 is at the same position as when the substrate to be processed is loaded at the end of the coating process, in other words, the Z phase indicated by the symbol S1 coincides with that at the end of the coating process. When facing the optical sensor (Fig. 6)
(See (A)), and when an arbitrary position of the spin chuck 14 is at a position different from the position when the substrate to be processed is loaded, in other words, as an example, the Z phase indicated by the symbol S1 is more than that when the spin chuck 14 is stopped. In the case where the position is shifted to a later position and faces the optical sensor (see FIG. 6B), the rotation state when the origin position signal is input when the low speed rotation is started after the processing is different. In other words, in the case shown in (C), the rotation can be stopped after one rotation after the low speed rotation is started, in other words, when the rotation in the steady state is being performed. On the other hand, in the case of (D), the origin position signal is input at the time of acceleration when the rotation starts and shifts to the steady state, and even when the rotation is stopped, processing is performed due to the difference in inertia or pulse phase. It will stop at a position different from the start. Therefore, in any case including (D),
In particular, for the case shown in (D), after stopping at the end of the process, a plurality of rotations are made again by low-speed rotation to maintain the steady low-speed rotation, and in this state, stop by inputting the origin position signal. I am trying to let you. Therefore, due to multiple rotations, the Z
As shown in FIG. 6 (D), the phase is arranged at a position where after rotation, a rotation corresponding to a steady state in which the rotation amount is one rotation or more is obtained. Incidentally, by setting the low speed rotation in such a steady state, instead of preventing the shift of the stop position due to the inertia or the phase shift at the time of the stop, for example, after the pulse for the origin position signal, A pulse generated by excessive rotation and a signal for discriminating the rotation direction (A,
The B-phase signal) may be counted, and the counter may be rotated in the reverse direction to stop at the true stop position.

Next, the operation will be described.

FIG. 7 is a flow chart for explaining the operation of the controller 36, and this flow chart is the main routine for sequence control relating to the overall processing relating to the coating process. In the main routine, first, an initial setting process is executed (ST1). In this initial setting process, a chuck direction aligning process, which will be described later, is carried out and stopped at the position where the origin position signal is output. The orientation of such a chuck can be based on the orientation of the orientation flat of the substrate to be processed. Then, when this initial setting is completed, the process of carrying in the substrate to be processed is executed (ST
2). In this step, the substrate to be processed is loaded into the spin chuck 14 that has been oriented using the transport arm, and is placed and fixed on the spin chuck 14. Therefore, in the spin chuck 14, the orientation of the orientation flat of the substrate to be processed that is placed and fixed is the direction at the time of loading. Thereafter, the process process such as the coating process described in FIG. 3 is executed (ST3). When this process processing is completed, the output of the drive signal which has been continued to the servo motor 32 is stopped during the process processing time, that is, the coating process time.

On the other hand, after the process processing is completed, the spin chuck orientation processing is executed (ST4). In this process, as shown in FIG. 8, the detection state of the origin position signal output at the end of the process process, that is, when the rotation is stopped is determined (ST5). In this discriminating process, discriminating the origin of the spin chuck 14, which is an arbitrary position of the spin chuck 14 when the substrate to be processed is carried in, is executed. The origin in this case is determined by whether or not the origin position signal output by the Z phase of the rotary encoder 34 is detected at the end of the process processing. Then, when the origin is not detected, that is, in FIG.
As shown in (D), as an example, the Z phase 34B of the encoder 34 becomes Z after the drive time of the spin chuck 14 elapses.
If the phase is stopped in front of the detection sensor, set the enable state to enable the acquisition of the origin position signal and until the origin position signal is output.
Start the low speed rotation of the motor 32 (ST6, ST7, S
T8). This state is indicated by reference numeral S1a in FIG.
It continues until the origin position signal indicated by is output.

Further, in the origin determination, as shown in FIG. 6A, when the origin position signal (S1) is output at the same time as the end of the process processing, or the rotation is continued by the processing of steps ST6 to ST8. If the origin position signal (S1) is output during the process, the disable state is set to disable the acquisition of the origin position signal, and the speed is slower than during process processing for a predetermined time. In this embodiment, the motor 32 is rotated and stopped for 0.5 seconds (ST9, ST10, ST11).
Then, the spin chuck 14 that is rotating at a low speed to a steady state in which the rotation state is stabilized by the low speed rotation for a predetermined time is
The origin determination is performed again, and this processing is repeated while the origin position signal is output (ST12). This allows
As shown in FIG. 6D, the spin chuck 14 positions the Z phase behind the optical sensor,
The rotation amount is set to a steady rotation or a state in which the rotation is close to the steady rotation, so that the positional deviation due to inertia or the positional deviation due to the phase difference due to the stop during the transition period such as acceleration is prevented.

Therefore, in step ST13, when the origin position signal for the origin determination is output, the origin position signal from this point is taken in, in other words, the origin for setting the stop position of the spin chuck 14 is set. Allowing the position signal to be taken in, the spin chuck 14 is rotated at a steady rotation. Then, when the origin position signal is output during the rotation process, the motor 32 is stopped and the state of waiting for the origin position signal to be output is set again (ST1).
4, ST15, ST16). When such a process is completed, the process proceeds to the carry-out process (ST17), and in the men-routine, it is determined whether or not the target substrate for which the orientation has been carried out is the final part carried into the coating process (ST1).
8) In the case of what is called the final application process for each lot, the sequence control for that lot is terminated.

Thus, once the process processing is completed,
Since the spin chuck 14 can be steadily rotated at a low speed to set the state in which the output error of the origin position signal or the positional deviation due to the inertia is prevented, it is possible to determine the state in which the stop at the true stop position is required. Therefore, it is possible to easily and accurately match the direction of the spin chuck when loading the substrate to be processed with the direction when unloading the substrate after the coating process.

It should be noted that the above enable and disable represent that the origin position signal is valid / invalid.

The origin position signal is an ES (Emergence) signal provided in a pulse generator (not shown) of the control unit 36.
ncy Stop) terminal. When the control signal (origin position signal) is input to the ES input terminal regardless of the movement amount information (pulse train) given to the motor driver (driving circuit 38), the pulse generator immediately stops the payout of the pulse train.

Therefore, the enable state means a state in which the origin position signal can be taken in (valid), and the disable state means a state in which the origin position signal cannot be taken in (invalid), and a hard port (not shown) is turned on. It can be controlled by turning it off.

According to this embodiment, the Z-phase signal formed simply for outputting the emergency stop signal is simply monitored, as compared with the processing for calculating the deviation of the number of pulses which is usually used in the position control. Since it is good, control can be performed easily. The present invention can be applied not only to the coating device described in the above embodiment but also to a developer, a scrubber, or the like.

[0040]

As described above, according to the present invention, the direction at the time of loading and unloading of the substrate to be processed can be obtained only by monitoring the origin position signal using the Z phase of the rotary encoder at the end of the coating process. It becomes possible to make a match. Moreover, since the reference for aligning can be performed under steady rotation regardless of the orientation of the spin chuck at the end of the coating process, misalignment during stoppage during transition such as acceleration is performed. Can be eliminated. Therefore, it becomes possible to save the time and effort required for the orientation of the spin chuck, thereby improving the throughput in the semiconductor manufacturing process.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a main configuration of a resist coating apparatus which is an example of a rotation processing apparatus according to the present invention.

FIG. 2 is a perspective view for explaining an overall configuration of an apparatus for implementing a substrate processing system in a resist processing apparatus.

FIG. 3 is a schematic diagram for explaining a coating processing section of the resist coating apparatus shown in FIG.

FIG. 4 is a schematic diagram showing a configuration of a motor control unit used in the coating processing unit shown in FIG.

5 is a timing chart for explaining an operation of an encoder attached to the motor shown in FIG.

FIG. 6 is a timing chart for explaining the operation of the main configuration shown in FIG.

FIG. 7 is a flowchart for explaining the operation of the control unit shown in FIG.

FIG. 8 is a flowchart for explaining a subroutine of the operation shown in FIG.

[Explanation of symbols]

 32 motor 34 rotary encoder 34B origin position signal slit (Z phase) 36 controller

Claims (2)

[Claims] 1. A rotation processing apparatus for forming a uniform coating film on a substrate by dropping or continuously supplying a resist solution to a substrate having a rotation position reference portion fixed on a rotatable mounting table. A means for rotationally driving the mounting table, and a controller for stopping the rotation driving means at the end of the processing, and rotating the rotation driving means for positioning after the processing is completed at a lower speed than the steady processing. Signal output means for outputting a synchronization signal for each rotation with reference to the start of rotation for the processing of the rotation drive means, and the control section receives the synchronization signal and performs the positioning rotation. The rotation processing device is characterized in that the rotation driving means is stopped when the synchronization signal is input after the rotation of the rotation signal is started. 2. The control unit according to claim 1, wherein the control unit stops the rotation driving unit at the time when the synchronization signal is input after the rotation driving unit is stopped and the steady state is reached at a low speed. Characteristic rotation processing device.