JPH0831512B2 - Substrate clamp mechanism for substrate processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate clamping mechanism for a substrate processing apparatus, and more particularly to a substrate clamping apparatus which applies torque control or speed control to its substrate clamping mechanism provided in a process chamber or the like. Substrate clamp mechanism of.

[0002]

2. Description of the Related Art A typical structure of a conventional substrate clamp mechanism is shown in FIG. 31 is a substrate stage that receives the substrate 32 and supports it, 33 is a clamp ring that presses and fixes the peripheral edge of the substrate 32 from above, and 34 is the clamp ring 3.
3 is a cylinder mechanism for moving up and down. Cylinder mechanism 34
Shows only two sets as an example. In addition, illustration of other detailed configurations is omitted. In the cylinder mechanism 34, the clamp ring 33 is moved up and down by supplying or discharging air or oil 35. In addition, as another configuration in the related art, there is also a configuration in which the clamp ring 33 is lowered by its own weight to perform the substrate clamp operation.

[0003]

The above-mentioned conventional substrate clamp mechanism has the following problems. In the configuration that uses air or oil to drive the cylinder mechanism 34,
Since the descending speed of the clamp ring 33 cannot be accurately controlled when descending, the peripheral edge of the substrate 32 cannot be clamped by soft touch. Therefore, there is a possibility that the peripheral portion of the substrate may be damaged. In the worst case,
The substrate 32 may be damaged.

Further, in the structure in which the substrate is clamped by its own weight of the clamp ring 33, the substrate can be prevented from being damaged at the time of clamping. However, according to this configuration, the pressure at the time of clamping is weak, and the clamping pressure cannot be set to the required constant pressure. When the clamping pressure is weak, the adhesion between the substrate stage 31 and the substrate deteriorates, so that the substrate 3
There is a problem that the temperature control of No. 2 becomes incomplete and the characteristics of the substrate 32 are deteriorated.

An object of the present invention is to provide a substrate clamping mechanism for a substrate processing apparatus having an optimum substrate clamping function.

[0006]

A substrate clamping mechanism of a substrate processing apparatus according to the present invention includes a substrate stage for supporting a substrate, a clamp member for clamping a substrate arranged on the substrate stage, and a clamp member. and an electric drive mechanism for elevating the peripheral edge of the substrate by the clamp member
Substrate processing equipment that presses the part and clamps it on the substrate stage
A location of the substrate clamping mechanism to control the operation of the electric drive mechanism to the desired state, has a speed control means for controlling the speed of the clamping member in the elevating operation of the clamping member by the electric drive mechanism, the speed control means By
When the ramp member approaches the substrate, it is initially relatively fast.
Approach at constant speed and reduce approach speed before clamping
Contact the peripheral edge of the board at a relatively slow speed during clamping.
The clamp member is configured to softly touch and press the peripheral portion of the substrate so that the substrate is fixed.
Further, by providing the torque control means for adjusting the clamping pressure of the substrate by the clamping member, when the clamping member clamps the peripheral portion of the substrate, the clamping pressure is set to the optimum pressure.

[0007]

In the substrate clamp mechanism according to the present invention, the clamp member for fixing the substrate is configured to be moved up and down by an electric drive mechanism such as an electric servomotor, and a speed control means and a torque control means are added. The control is performed so that the speed of the clamp member at the time of contacting the substrate and the pressure for clamping the substrate are in a desired state. This allows
The clamp member softly contacts the peripheral edge of the substrate to prevent damage to the substrate, fixes the substrate with an optimum pressure, and brings the substrate and the substrate stage into close contact with each other in an optimum state.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows the mechanical components of the substrate clamping mechanism and the controller. The mechanical components are arranged in a processing container of a substrate processing apparatus (not shown). In FIG.
Reference numeral 1 is a substrate stage, 2 is a substrate arranged on the substrate stage, and 3 is a clamp ring arranged so as to be movable up and down above the substrate. The clamp ring 3 presses the peripheral edge of the substrate 2 in its lowered state and fixes (clamps) the peripheral edge of the substrate 2 with a required pressure. Reference numeral 4 is a drive unit for moving the clamp ring 3 up and down. In the illustrated example, two sets of drive units 4 are shown. FIG. 2 is a longitudinal cross-sectional view of a main part showing a positional relationship between the substrate stage 1, the substrate 2, and the clamp ring 3 in a clamped state.

The drive unit 4 has an electric structure,
For example, the electric servomotor 5 and the encoder 6 that measures the operation amount of the servomotor 5 are provided. Drive unit 4
Are fixed to the mounting plate 4a. A plurality of cylinder mechanisms 7 are provided below the clamp ring 3 at predetermined positions. The cylinder mechanism 7 includes an upper cylinder 7a attached to the lower surface of the clamp ring 3 and a fixed lower cylinder 7b. The upper cylinder 7a is the lower cylinder 7
It is fitted to b and is attached so as to be vertically movable in the axial direction. Brackets 8 and 9 are fixed to the upper cylinder 7a and the lower cylinder 7b, respectively, and a screw type movable mechanism 10 is disposed between the brackets 8 and 9. When the rotating shaft of the screw type movable mechanism 10 rotates, the upper cylinder 7a moves up and down according to the rotating direction. Therefore, the clamp ring 3 also moves up and down together with the upper cylinder 7a.

A gear 11 is attached to the lower end of the rotary shaft of the screw type movable mechanism 10. The gear 11 meshes with a gear 12 attached to the drive shaft of the servomotor 5. The rotary shaft of the screw-type movable mechanism 10 receives a rotational force from the servomotor 5 via the gears 11 and 12, and rotates in a desired direction.

The above-mentioned drive unit 4, cylinder mechanism 7,
When the servomotor 5 of the drive unit 4 rotates based on each configuration of the screw type movable mechanism 10, the upper cylinder 7a and the clamp ring are rotated in the corresponding direction and at the corresponding speed according to the rotation direction and the rotation speed. Move 3 The drive unit 4, the cylinder mechanism 7, and the screw type movable mechanism 10 are provided at equal intervals, for example, about 3 sets.

The rotation operation of the servo motor 5 of each drive unit 4 is controlled by a servo motor control unit 14, a speed control mechanism 16 and a clamp pressure control mechanism 18 provided in the controller 13. The servo motor control unit 14 or the like supplies a control signal for controlling the rotation operation of the servo motor 5 to the servo motor 5 via the servo motor driver 15. This control signal includes a speed control signal and a torque control signal. According to these control signals, when the clamp ring 3 descends to clamp the peripheral portion of the substrate 2, the descending speed is controlled so as to have a predetermined speed characteristic, and the clamping pressure becomes a predetermined constant pressure. Can be controlled to be.

In controlling the descending speed of the clamp ring 3,
At the beginning, the control is performed such that the substrate descends at a high constant speed, the descending speed is reduced before clamping, and the peripheral edge of the substrate is contacted and pressed at a very slow speed during clamping. That is,
A predetermined speed characteristic is set in advance in the speed control mechanism 16. The rotation speed of the servo motor 5 which operates according to the control signal is detected by the encoder 6 and given to the speed control mechanism 16. The speed control mechanism 16 compares the preset speed characteristic with the input actual speed and generates a desired speed control signal. This speed control signal is supplied to the servo motor 5 via the servo motor control unit 14, the servo motor driver 15, and the torque detector 17. In this way, the servomotor 5 controls the speed with the set speed characteristic as the target speed.

In controlling the clamp pressure of the clamp ring 3, the torque detector 17 connected to the output of the servo motor driver 15 is used. Torque detector 17
Detects the clamp pressure by the clamp ring 3 by detecting the current value of the control signal supplied to the servo motor 5. The detection signal of the torque detector 17 is supplied to the clamp pressure control mechanism 18. Clamp pressure control mechanism 18
Then, a current value for generating a predetermined clamp pressure is set, this set value is compared with the detected current value, and a torque control signal is generated so that the final detected current value matches the set value. The torque control signal is sent to the servo motor control unit 1
4, the servo motor driver 15, and the torque detector 17 are supplied to the servo motor 5.

The control of the rotation speed and the torque of the servomotor 5 is performed under the same condition for each of the plurality of servomotors 5. By the speed control of the electric servomotor 5, the clamp ring 3 approaches the substrate 2 with a predetermined speed characteristic while being held parallel to the substrate 2, and contacts the substrate 2 at a slow speed. As a result, soft touch substrate contact can be performed. Further, by controlling the torque of the electric servomotor 5, the peripheral edge of the substrate 2 is pressed with a required constant clamping pressure. As a result, sufficient adhesion can be obtained between the substrate 2 and the substrate stage 1.

The clamp ring 3 for clamping
It is also possible to control the clamping pressure according to the moving stroke of the. That is, the clamp ring 3 can be configured to operate at a set speed until the clamp is performed, operate by torque control after the clamp, and hold the clamp at the set torque. Further, since the position control is performed, the clamping can be performed by gradually changing the clamping pressure according to the clamping from the set position. In this case, weakening the clamp pressure results in a soft clamp, and increasing the clamping pressure results in a hard clamp.

The servo motor control unit 14 can be provided with an alarm mechanism. According to the alarm mechanism, when the substrate 2 is clamped, the alarm is generated when the clamping pressure or the moving stroke for clamping becomes an abnormal value compared with the set value. Further, the clamp operation can be stopped at the same time when the alarm is issued.

The servo motor control unit 14 can be further provided with a preventive maintenance mechanism. According to this preventive maintenance mechanism, for example, by continuously detecting the clamp pressure, when a failure may occur in the substrate clamp mechanism, the failure occurrence is predicted in advance and the entire apparatus is maintained.

[0019]

As is apparent from the above description, since the structure for optimally controlling the approaching speed of the clamp member and the clamp pressure at the time of substrate clamping is provided, the substrate is clamped by the soft touch and the optimum pressure is applied. The substrate can be clamped. This can prevent damage to the substrate, improve the adhesion between the substrate and the substrate stage, and improve the temperature characteristics of the substrate.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a mechanical configuration portion and a control device of a substrate clamp mechanism according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part in FIG.

FIG. 3 is a perspective view showing a conventional substrate clamp mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate stage 2 ... Substrate 3 ... Clamp ring 4 ... Electric drive device 5 ... Servo motor 6 ... Encoder 7 ... Cylinder mechanism 10 ... Screw type movable mechanism 11, 12 ... Gear 13 ... Control device 14 ... Servo motor control unit 15 ... Servo motor driver 16 Speed control mechanism 17 Torque detector 18 Clamp pressure control mechanism

Claims (1)

[Claims] 1. A substrate stage for supporting a substrate, a clamp member for clamping the substrate arranged on the substrate stage, and an electric drive mechanism for moving the clamp member up and down, the substrate being provided by the clamp member. of
A base for holding the peripheral edge and clamping it on the substrate stage.
First when the substrate clamping mechanism of the plate processing apparatus, the speed of the clamping member in the elevating operation of the clamping member by the electric drive mechanism controls the electric drive mechanism, the clamping member approaches the substrate
Approaches at a relatively fast constant speed, and before clamping
Reduce the approach speed, and move at a relatively slow speed during clamping.
The speed control means for controlling so as to contact the peripheral portion of the substrate, and the clamp member clamps the substrate.
Torque control to adjust the pump pressure to a predetermined constant pressure.
A substrate clamping mechanism for a substrate processing apparatus, comprising a control means .