JP2002198353A - Plasma pcocessing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a throughput by reducing the transfer time of a substrate in a plasma processing system. SOLUTION: A clamp ring hoisting mechanism 57 is coupled with a driving motor 71 by a belt pulley mechanism. A substrate thrust mechanism 58 comprises a thrust board 74 on which thrust pins are fixed, cam followers 91A, 91B arranged on the thrust board 74, and a grooved cylindrical cam 87 in which cam grooves 89A, 89B are formed. The grooved cylindrical cam 87 is coupled with the driving motor 71 by a belt pulley mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus used for a thin film forming process, a fine processing, and the like in manufacturing semiconductor devices, liquid crystal display panels, solar cells, and the like.

[0002]

2. Description of the Related Art In recent years, in a plasma processing apparatus, various devices for realizing high precision, high speed, large area, low damage, and high reliability have been developed in order to enhance the functionality of the device and reduce the processing cost. Attempts have been made. In particular, in order to improve the film quality uniformity in the substrate in the thin film forming process and the dimensional accuracy in the dry etching process used as fine processing, it is necessary to control the temperature in the substrate surface uniformly and precisely. is there. For this reason, a clamp ring is provided to hold the periphery of the substrate against the substrate holder, and the back surface of the substrate is filled with an inert gas to improve the temperature transmission from the substrate holder to the back surface of the substrate, thereby achieving a uniform substrate temperature. A plasma processing apparatus has been proposed.

FIG. 7 shows such a conventional plasma processing apparatus (reactive ion etching apparatus). In the vacuum chamber 1, a substrate holder 2 and an upper electrode 3 facing the substrate holder 2 are accommodated. The lower electrode 4 is provided on the substrate holder 2.
The lower electrode 4 is connected to a high-frequency power source 7 for generating plasma.

[0006] A clamp ring 9 is provided for pressing the outer peripheral portion of the substrate 8 against the substrate holding table 2. The clamp ring elevating mechanism 11 for elevating and lowering the clamp ring 9 includes an elevating ring 12 arranged at the bottom of the vacuum chamber 1 so as to surround the substrate holder 2. A plurality of cylindrical portions 12a extending upward are provided on the upper surface of the elevating ring 12. On the other hand, the clamp ring 9 has the cylindrical portion 12
A plurality of insertion holes 9a are provided corresponding to a, and a spring 13 is inserted into the insertion holes 9a. A clip 14 is fixed to one end of the spring 13. further,
The spring 13 is inserted into the cylindrical portion 12a, and the other end is fixed to the elevating ring 12. The clamp ring 9 is pulled toward the substrate holder 2 by the spring 13, whereby the clamp ring 9 presses the substrate 8 against the substrate holder 2.

[0005] Elevating shafts 16 are inserted into a plurality of insertion holes 1a provided at the bottom of the vacuum chamber 1, respectively. The elevating shaft 16 is inserted through a bellows 17 for isolating the inside of the vacuum chamber 1 from the atmosphere. Further, the elevating shaft 16 has a distal end fixed to the elevating ring 12 and a proximal end connected to a ball screw 18. A nut 18a of each ball screw 18 is connected to a timing pulley 19, and each timing pulley 19 is connected to a timing belt 21, another timing pulley 22, and a speed reducer 23.
Is connected to the drive motor 24 via the. When the drive motor 24 operates and the nut 18a of the ball screw 18 moves up and down, the elevating shaft 16 moves up and down. When the elevating shaft 16 moves up and down, the elevating ring 12 moves up and down, whereby the clamp ring 9 moves up and down with respect to the substrate holder 2.

Further, the plasma processing apparatus includes a substrate push-up mechanism 26 for separating the substrate 8 from the substrate holding table 2 after the processing is completed. This substrate push-up mechanism 2
In the case of No. 6, a plurality of insertion holes 27 penetrating the substrate holding table 2 and the bottom of the vacuum chamber 1 are provided, and a push-up pin 28 is inserted into each of the insertion holes. The lower end of each push-up pin 28 is accommodated in a box 29 fixed to the outside of the bottom of the vacuum chamber 1 corresponding to the insertion hole 27. The box 29 houses a mechanism for raising and lowering the push-up pin 28 having a lever, a cam follower, and the like (not shown). The mechanisms in each box 29 are connected by a rod (not shown) provided outside the box 29 so that the push-up pins 28 move up and down in synchronization. The box 29 communicates with the inside of the vacuum chamber 1 through the insertion hole 27, but the inside of the box 29 and the atmosphere are shut off by a sealing mechanism.

The substrate push-up mechanism 26 is driven by the same drive motor 25 as the transfer arm 31 for transferring the substrate 8 into the vacuum chamber 1.

In FIG. 7, reference numeral 32 denotes a reaction gas supply source, 3
Reference numeral 3 denotes a vacuum exhaust unit; 34, an inert gas supply unit for filling an inert gas between the substrate holding table 2 and the substrate 8;
Reference numeral 6 denotes a door 36 for opening and closing a loading / unloading port 37 of the substrate 8 to / from the vacuum chamber 1.

[0009]

As described above, in the conventional plasma processing apparatus in which the clamp ring elevating mechanism 11 and the substrate push-up mechanism 26 have separate drive systems each having an independent drive source, one of the operations is performed by a sensor. Since it is necessary to operate the other after the detection, the control is complicated and the time required for substrate transfer is long. For example, the substrate holder 2
When peeling the substrate 8 from the
Is detected to be separated from the substrate 8 and the substrate holding table 2 and then the substrate push-up mechanism 26 needs to be operated.

Further, if the clamp ring lifting mechanism 11 and the board lifting mechanism 26 have separate drive systems, the number of components including those requiring maintenance is increased, and high component processing accuracy is required.

Further, it is difficult to make the substrate push-up mechanism 26 the same drive system as the drive mechanism of the transfer arm 31, particularly when the substrate is large, from the viewpoint of scratches and dust on the back surface of the substrate. .

Further, in the conventional plasma processing apparatus, especially when the substrate 8 is large and the electrostatic attraction acting between the substrate 8 and the substrate holding table 2 is large after the substrate processing is completed, the substrate push-up mechanism 26 is used. During the peeling operation, the substrate 8 may be displaced, damaged, or the like. On the other hand, if the push-up speed is reduced to prevent these displacements and breakage, the throughput will be reduced.

Accordingly, an object of the present invention is to improve the throughput by reducing the substrate transfer time and to improve the operation reliability of these mechanisms in a plasma processing apparatus having a clamp ring elevating mechanism and a push-up mechanism. It is another object of the present invention to enable a plasma processing apparatus to reliably and quickly peel a substrate from a substrate holding table without causing damage or displacement of the substrate.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a clamp ring for pressing an outer peripheral portion of a substrate against a substrate holder, a clamp ring lifting mechanism for lifting and lowering the clamp ring, A plasma processing apparatus comprising: a substrate push-up mechanism that raises and lowers push-up pins inserted through the substrate holding table, wherein the clamp ring lifting mechanism and the substrate push-up mechanism are driven by a common drive motor, and are synchronously driven. An object of the present invention is to provide a plasma processing apparatus that operates.

In the plasma processing apparatus of the present invention, the clamp ring elevating mechanism and the substrate push-up mechanism are operated synchronously by the common driving motor. Therefore, after detecting the end of operation of one of the mechanisms by a sensor or the like, the other is detected. There is no need to operate the mechanism. Therefore, the control is simple, and the substrate transfer time to the substrate holding table can be reduced. In addition, the operation reliability is high, and it is possible to prevent dust generation and device damage due to trouble in transporting the substrate. Further, since the clamp ring elevating mechanism and the substrate lifting mechanism are driven by a common driving motor, the number of components including those requiring maintenance can be reduced, and high component processing accuracy is not required. Furthermore, since the drive system of the push-up mechanism is separate from the transfer arm, there is no need to reduce the speed of loading the substrate by the transfer arm even when reducing the rising speed of the push-up pins.

Specifically, the clamp ring lifting mechanism is connected to the driving motor by a first belt pulley mechanism, and the substrate lifting mechanism includes a lifting plate to which lifting pins are fixed, and a lifting plate. A cam follower provided on the plate and a cylindrical groove cam having a cam groove with which the cam follower engages are provided, and the cylindrical groove cam is connected to the driving motor by a second belt pulley mechanism.

The substrate push-up mechanism is connected to a clamp ring elevating mechanism and a common driving motor by a engagement between a cylindrical groove cam and a cam follower and a belt pulley mechanism. Is achieved. Therefore, in order to synchronize these mechanisms, electrical control such as a change in motor speed is not required, and operation stability is high. Also, by changing the shape of the cam groove,
Delay of raising and lowering the push-up pin with respect to lifting and lowering of the clamp ring, lowering of the lifting speed of the push-up pin at the start of lifting, and the like can be easily realized.

More specifically, the cylindrical groove cam has two symmetrically formed cam grooves having the same shape.
Two cam followers are arranged on the push-up plate symmetrically with respect to the cylindrical groove cam, and each cam follower is engaged with a corresponding cam groove.

In this case, since the lifting plate to which the lifting pin is fixed is guided by the two cam grooves and the two cam followers, the posture of the lifting plate during the raising and lowering is reliably maintained. Therefore, the reliability of the peeling operation of the substrate from the substrate holding table by the push-up pins is high.

It is preferable that the apparatus further comprises a controller for detecting an output torque of the driving motor from an output signal of a driver of the driving motor, and controlling rotation of the driving motor based on the detected output torque.

The residual attraction force due to electrostatic attraction acting between the substrate and the substrate holding table after the substrate processing becomes a load acting on the push-up shaft when the substrate is pushed up, and when the load acts, the output torque of the driving motor is increased. Increase. Therefore, by controlling the rotation speed and the rotation direction of the driving motor based on the output torque, even when the residual suction force exists, the displacement of the substrate, the breakage of the substrate,
The substrate can be reliably peeled from the substrate holder without causing device damage or the like due to the movement of the charged charge, and dust generation and device damage due to troubles at the time of peeling the substrate can be prevented.

For example, when the output torque exceeds a predetermined value, the controller causes the driving motor to repeat forward and reverse rotations, and causes the drive shaft to repeatedly push up the substrate.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention shown in the drawings will be described in detail. FIG. 1 shows a reactive ion etching (RIE) apparatus which is a plasma processing apparatus according to an embodiment of the present invention. The vacuum chamber 41 of the RIE apparatus is connected to a reaction gas supply source 32 and a vacuum exhaust unit 43. The vacuum chamber 41 is provided with a loading / unloading port 41a for the substrate 44. When the door 46 is opened, the transport arm 47 passes through the loading / unloading port 41a.
The substrate 44 is loaded or unloaded into the device 1.

In the vacuum chamber 41, a substrate holder 48 is provided.
And the upper electrode 4 is opposed to the substrate holding table 48.
9 are accommodated. The substrate holder 48 has a lower electrode 51
The lower electrode 51 is connected to a high frequency power supply 53 for generating plasma. Further, a flow path 48b is provided in the substrate holding table 48, and this flow path 48b is provided.
b is connected to an inert gas supply source 54 for filling an inert gas between the substrate holding table 48 and the substrate 44.

The RIE apparatus includes a clamp ring 56 for pressing an outer peripheral portion of the substrate 44 against the substrate holder 48.
And a clamp ring raising / lowering mechanism 57 for raising and lowering the clamp ring 56. Further, the RIE apparatus includes a substrate pushing-up mechanism 58 for separating the substrate 44 from the substrate holding table 48 after the processing is completed. The clamp ring lifting mechanism 57 and the substrate lifting mechanism 58
Are driven by the same driving motor 71 as described later.

Referring to FIGS. 1 and 2, the clamp ring 56 and the clamp ring elevating mechanism 57 will be described. The clamp ring 56 has a rectangular frame shape, and is disposed above the substrate holder 48.

The clamp ring raising / lowering mechanism 57 has a rectangular frame-shaped lifting / lowering ring 59 arranged at the bottom of the vacuum chamber 41 so as to surround the substrate holder 48.
On the upper surface of the elevating ring 59, a plurality (up to four in this embodiment, but preferably from three to eight) of cylinder portions 59a extending upward are provided. On the other hand, the clamp ring 56 is provided with four insertion holes 56a corresponding to the respective cylindrical portions 59a, and these insertion holes 56a are
The springs 61 are respectively inserted. Each spring 61
A clip 62 is fixed to one end. Further, each spring 61 is inserted into the cylindrical portion 59 a, and the other end is fixed to the elevating ring 59. The clamp ring 56 is pulled toward the substrate holder 48 by a spring 61, whereby the clamp ring 56 presses the substrate 44 against the substrate holder 48.

A lifting shaft 63 is inserted into each of the four insertion holes 41b provided at the bottom of the vacuum chamber 41. The elevating shaft 63 is inserted into a bellows 64 for shielding the inside of the vacuum chamber 41 from the atmosphere.
The elevating shaft 63 has a distal end fixed to the elevating ring 59 and a proximal end connected to the ball screw 66. The nut 66a of each ball screw 66 is a timing pulley 67A.
And each timing pulley 67A is connected to a drive motor 71 which is a servomotor via a timing belt 68A, another timing pulley 67B, and a speed reducer 69A. The driver 72 of the driving motor 71 is connected to the controller 73. The four ball screws 66 are connected two by two by a synchronization bar (not shown), so that the ascending and descending of all the elevating shafts 63 are reliably synchronized.

When the driving motor 71 operates, the ball screw 6
When the nut 66a rotates, the elevating shaft 63 moves up and down. When the elevating shaft 63 moves up and down, the elevating ring 59
Moves up and down, whereby the clamp ring 9 moves up or down with respect to the substrate holder 2.

Next, the substrate lifting mechanism 58 will be described with reference to FIGS. First, the substrate push-up mechanism 58 includes a push-up plate 74. In addition, vacuum chamber 4
The upper ends of a pair of linear shafts 76A and 76B extending in the vertical direction are fixed to the outside of the bottom of the first shaft. Linear shafts 76A and 76B are inserted through linear bushes 77A and 77B provided on the push-up plate 74, respectively.
The lifting plate 74 is guided to move up and down. A spring receiver 78 is fixed to lower ends of the linear shafts 76A and 76B, and a spring 79 is compressed between the spring receiver 78 and the lower surface of the push-up plate 74. The push-up plate 74 is urged vertically upward by the spring 79.

A plurality of (six in this embodiment) push-up pins 81 are fixed to the push-up plate 74. Each push-up pin 81 is inserted into an insertion hole 82 that penetrates through the substrate holding table 48 and the bottom of the vacuum chamber 41. A socket 83 is fixed to the lower end of each push-up pin 81, and the shaft 83 is fixed to the push-up plate 74 by fitting the socket 83 into a notch 74 a provided in the push-up plate 74. are doing. Further, each push-up pin 81 is inserted through the bellows 84. The bellows 84 is fixed to the bottom of the vacuum chamber 41 so as to surround the upper end side or the insertion hole 82, and the lower end side is fixed to the socket 83. The bellows 84 shields the inside of the vacuum chamber 41 from the atmosphere.

A vertically extending support shaft 86 is fixed to the outside of the bottom of the vacuum chamber 41. A cylindrical groove cam 87 is attached to the support shaft 86 by a bearing 88 (only shown in FIG. 3). Have been. Therefore, the cylindrical groove cam 87 is rotatable around the vertical axis L. A through hole 74b is provided at the center of the push-up plate 74, and a cylindrical groove cam 87 is disposed through the through hole 74b. The size of the through hole 74b is set to be larger than the diameter of the cylindrical groove cam 87, so that the rotation of the cylindrical groove cam 87 about the axis L is not hindered.

As shown in FIG. 4 and FIG.
The outer periphery of 7 is provided with two cam grooves 89A, 89B. These cam grooves 89A and 89B have the same shape and are formed symmetrically with respect to the axis L. Also,
In the vicinity of the through hole 74b of the push-up plate 74, a pair of cam followers 91 that engage with the cam grooves 89A and 89B.
A and 91B are attached by a bracket 92. As shown in FIGS. 3 and 4, these cam followers 91A and 91B are arranged symmetrically with respect to the cylindrical groove cam 87 (the axis L). In addition, individual cam followers 9
The rotation axes of 1A and 91B are eccentric, and the push-up plate 74
Fine adjustment that keeps the camera horizontal is possible. Furthermore,
Since the push-up plate 74 is urged upward in the vertical direction by the spring 79 as described above, the cam followers 91A and 91B are connected to the cam grooves 89A and 89B shown in FIG. Is always in contact with the upper surface 89a.

A timing pulley 67C is fixed to the lower end of the cylindrical groove cam 87. This timing pulley 67
C is a driving motor 7 common to the clamp ring elevating mechanism 57 via timing belts 68C and 68D, another timing pulley 67C and speed reducers 69A and 69B.
1 and when the driving motor 71 rotates, the cylindrical groove cam 87 rotates. That is, in the present embodiment, the substrate push-up mechanism 58 is not driven by the drive motor 47 a of the transfer arm 47, but is driven by the drive motor 71 of the clamp ring elevating mechanism 57.

Next, the operation of the RIE apparatus will be described. First, reactive ion etching will be described.
The inside of the vacuum chamber 41 is depressurized to a predetermined degree of vacuum by the vacuum exhaust means 43, and a reaction gas is supplied from the reaction gas supply source 32. Further, the substrate holding table 4 is supplied from the inert gas supply source 54.
An inert gas is supplied between the substrate 8 and the substrate 44. When a high frequency voltage is applied to the lower electrode 51 from the high frequency power supply 53,
Plasma is generated in the vacuum chamber 41, and the substrate 44 is etched according to a resist pattern formed in advance.

Next, carrying out of the substrate 44 after the reactive ion etching will be described. When the driving motor 71 rotates forward, the speed reducer 69A and the timing belts 68A, 68
The rotation of the drive motor 71 is transmitted to the nut 66a of the ball screw 66 via B and the timing pulleys 67A and 67B, and the elevating shaft 63 is raised. Elevating shaft 6
When 3 rises, the elevating ring 59 rises. Further, the clamp ring 56 is pushed up by the tip of the cylindrical portion 59a and rises, and floats up with respect to the substrate 44 and the substrate holding base 48. On the other hand, the forward rotation of the driving motor 71 is
9A, 69B, the timing belts 68C, 68D, and the timing pulleys 67C, 67D via the cylindrical groove cam 87.
And the cylindrical groove cam 87 rotates. Cylindrical groove cam 8
When the cam 7 rotates, the push-up plate 74 is raised by the engagement between the cam grooves 89A and 89B and the cam followers 91A and 91B. When the push-up plate 74 is raised, the six push-up pins 81 are raised, and the tips of the pins push up the substrate 44 and separate from the surface of the substrate holding table 48. Thereafter, the substrate 44 is carried out of the vacuum chamber 41 by the transfer arm 47.

When the substrate 44 is carried in, first, the substrate 44 is placed on the tip of the push-up pins 81 projecting from the substrate holding table 48 by the transfer arm 47. Thereafter, the drive motor 71 rotates in the reverse direction, the push-up pins 81 descend, the substrate 44 is placed on the substrate holder 48, and the clamp ring 56 descends.

The clamp ring raising / lowering mechanism 57 and the substrate lifting mechanism 58 include a clamp ring 56 and a lifting pin 8.
1 is moved up and down at the timing and speed shown in FIG.

In FIG. 6, the horizontal axis shows the rotation angle of the output shaft of the driving motor 71, and the vertical axis shows the amount of rise of the clamp ring 56 and the push-up pin 81. 6, the origin I of the rotation angle corresponds to the lowest position of the push-up pin 81 (the position where the tip does not protrude from the substrate holder 48) and the lowest position of the clamp ring 56. That is, the origin I corresponds to a state in which the substrate 44 is placed on the substrate holder 48 and the outer periphery of the substrate 44 is pressed against the substrate holder 48 by the clamp ring 56 (at the time of the reactive ion etching process). ing. In FIG. 6, the origin II of the rotation angle corresponds to the highest position of the push-up pin 81 and the clamp ring 56. That is, the origin II is such that the tip of the push-up pin 81 projects from the substrate holder 48 and the clamp ring 56 is
8 corresponds to a state where the substrate 44 is lifted (when the substrate 44 is loaded and unloaded).

First, the normal rotation of the driving motor 71 (the rising of the clamp ring 56 and the push-up pin 81) will be described. From the origin I to the rotation angle a1, that is, at the beginning of the normal rotation start of the driving motor 71, the clamp ring 56
Rises at a low speed, but the push-up pin 81 does not rise.
Initially, the reason why the clamp ring 56 rises at a low speed is to prevent reaction products on the clamp ring 56 from dropping onto the substrate 44. The reason why the push-up pins 81 do not rise is that the clamp ring 56 is separated from the board 44 before the push-up pins 81 push the substrate.

The push-up pin 81 starts rising at a low speed from the rotation angle a1. The reason why the substrate 44 is gently pushed up at the beginning of the push-up is to prevent the substrate 44 from being damaged. Further, the clamp ring 56 is rotated from the rotation angle a1.
The ascending speed accelerates.

The speed of the clamp ring 56 decreases from the rotation angle a2. This is to prevent the reaction product from dropping from the clamp ring 56 to the substrate 44 due to the impact when the clamp ring 56 stops rising.

The rising speed of the push-up pin 81 increases from the rotation angle a3. This is because the substrate 44 has already been peeled to some extent from the substrate holding table 48, so that the substrate 44 does not break even if the lifting speed of the push-up pins 81 is high.

The lifting of the clamp ring 56 is completed at the rotation angle a4, and the position of the clamp ring 56 in the vertical direction is maintained until the origin position II. On the other hand, the push-up pin 81 rises at a low speed from the rotation angle a4 to the origin position II.

The reason why the maximum rising amount S2 of the clamp ring 56 is set to be larger than the maximum rising amount S1 of the push-up pin 81 is to prevent interference between the transfer arm 47 and the clamp ring 56. That is, when the substrate 44 is carried in and out, the transfer arm 4 passes under the clamp ring 56.
7 moves to the substrate holding table 48. The speed reducer 69B is provided to make the maximum rising amount S2 of the clamp ring 56 larger than the maximum rising amount S1 of the push-up pin 81 as described above. However, the maximum rising amounts S1 and S2 may be set as described above according to the diameter of the timing pulley.

The downward movement of the clamp ring 56 and the push-up pin 81 when the driving motor 71 rotates in the reverse direction is the reverse of the normal rotation as shown by the rotational positions a5 to a8 in FIG. That is, after the push-up pins 81 are completely lowered and the substrate 44 is placed on the substrate holding table 48, the clamp ring 56 is lowered to the substrate 44.

The raising and lowering of the clamp ring 56 shown in FIG. 6 is realized by controlling the rotation speed of the driving motor 71 by the controller 73.

On the other hand, the lifting and lowering of the push-up pin 81 shown in FIG. 6 is realized by the shapes of the cam grooves 89A and 89B. That is, as shown in FIG. 5, the cam grooves 89A and 89B of the cylindrical groove cam 87 are arranged in the order from the left side in the figure to the horizontal portion 89b, the first inclined portion 89c, the second inclined portion 89d and the second inclined portion 89d.
An inclined portion 89e is provided. The horizontal portion 89b is a portion where the push-up plate 74 does not move up and down. In the first, second and third inclined portions 89c, 89d, 89e, the push-up plate 74 moves up and down. Since the second inclined portion 89d has a larger inclination angle than the first and third inclined portions 89c and 89e, the second inclined portion 89d
Is a plate 74 pushed up from the first and inclined portions 89c and 89e.
The lifting speed is fast.

The residual attraction force due to electrostatic attraction acting between the substrate 44 and the substrate holding table 48 after the substrate processing is as follows:
When the substrate is pushed up, the load acts on the push-up pins 81, and when the load acts, the output torque of the drive motor 71 increases. Therefore, in the present embodiment, when the substrate 44 is carried out, the rotation of the driving motor 71 is controlled according to the output torque of the driving motor 71. That is, the controller 73 detects the output torque of the drive motor 71 from the output signal of the driver 72 of the drive motor 71, and when the output torque exceeds a predetermined value, causes the drive motor 71 to repeat forward and reverse rotations. , Push-up pin 8
1 repeats pushing up of the substrate 44.

By repeatedly pushing up with the push-up pins 81, the push-up pins 81 on the rear surface of the substrate 44 are formed.
Is gradually separated from the substrate holder 48, and the contact area between the back surface of the substrate 44 and the substrate holder 48 decreases. As a result, the residual charge between the substrate holder 48 and the substrate 44 is electrically neutralized by using the inert gas remaining on the rear surface side of the substrate 44 as a medium, and the residual adsorption force is reduced. Therefore, in the present embodiment, even when the residual suction force is present, the substrate is reliably separated from the substrate holding table without causing a displacement of the substrate, breakage of the substrate, etc. Dust and device damage can be prevented.

The predetermined value of the output torque may be set to be equal to or less than the limit value of the shear stress (for example, 0.5 kg · m) at which the substrate 44 is not damaged. The predetermined value can be determined by the following method. First, the substrate 44 is pushed up by the push-up pins 81 without any residual charge. in this case,
The torque detected by the output signal of the driver 72 of the driving motor 71 is determined by the total weight of the substrate lifting mechanism 58 and the substrate 44, the force acting on the lifting plate 74 from the spring 79, and the like. Reproducible unless assembled. Therefore, the detected torque may be stored in the controller 73 as a predetermined value.

When the output torque exceeds a predetermined value, the forward rotation of the driving motor 71 is once decelerated or stopped, and then the forward rotation speed of the driving motor 71 is increased. The occurrence of breakage and the like can be prevented.

In the present embodiment, since the discharge plasma process is not used and no high voltage electrode or the like for corona discharge is provided inside the vacuum vessel, dust is generated from the vacuum vessel by plasma, and impurities from the electrode material are removed. No pollution or dusting.

The present invention is not limited to the above reactive ion etching apparatus, but can be applied to other plasma processing apparatuses including a plasma CVD apparatus, a sputtering apparatus, and an ashing apparatus.

[0055]

As is apparent from the above description, in the plasma processing apparatus of the present invention, the clamp raising / lowering mechanism and the substrate lifting mechanism are operated synchronously by the common driving motor. It is not necessary to operate the other mechanism after the detection by the sensor or the like, the control is simple, the throughput can be improved by shortening the substrate transfer time, and the operation reliability is high. Further, since the clamp ring elevating mechanism and the substrate lifting mechanism are driven by one driving motor, the number of components including those requiring maintenance can be reduced, and high component processing accuracy is not required.

Further, when the controller controls the rotation of the driving motor based on the output torque of the driving motor detected from the output signal of the driver, there is a residual suction force between the substrate holding table and the substrate. Even if the board is misaligned,
The substrate can be reliably peeled off from the substrate holding table without causing damage to the substrate, and dust and device damage due to troubles at the time of peeling the substrate can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a part of a clamp ring elevating mechanism.

FIG. 3 is an exploded perspective view showing the push-up mechanism.

FIG. 4 is an exploded perspective view showing a cylindrical groove cam and a cam follower.

FIG. 5 is a development view of the outer peripheral surface of the cylindrical groove cam.

FIG. 6 is a diagram for explaining lifting and lowering of a clamp ring and a push-up plate.

FIG. 7 is a schematic sectional view showing a conventional plasma processing apparatus.

[Explanation of symbols]

 41 Vacuum tank 41a Loading / unloading port 41b Insertion hole 42 Reaction gas supply source 43 Vacuum exhaust means 44 Substrate 46 Door body 47 Loading arm 47a Driving motor 48 Substrate holder 48a Alumina insulating layer 48b Channel 49 Upper electrode 51 Lower electrode 53 High frequency power supply 54 Inert gas supply source 56 Clamp ring 56a Insertion hole 57 Clamp ring elevating mechanism 58 Substrate pushing up mechanism 59 Elevating ring 59a Cylindrical part 61 Spring 62 Clip 63 Elevating shaft 64 Bellows 66 Ball screw 66a Nut 67A-67D Timing pulley 68A-68D Timing belt 69A, 69B Reducer 71 Driving motor 72 Driver 73 Controller 74 Thrust plate 74a Notch 74b Through hole 76A, 76B Linear shaft 77A, 77B Linear bush 78 Receptacle 79 Spring 81 Push-up pin 82 Insertion hole 83 Socket 84 Bellows 86 Support shaft 87 Cylindrical groove cam 88 Bearing 89A, 89B Cam groove 89a Upper surface of cam groove 89b Horizontal part 89c First inclined part 89d Second inclined part 89e Third inclined Part 91A, 91B Cam follower 92 Bracket L axis

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 FA01 GA01 KA45 5F004 AA06 AA14 BA04 BB21 BB22 BC06 CA05 5F031 HA33 LA07 LA13 MA28 MA32

Claims (5)

[Claims] 1. A clamp ring for pressing an outer peripheral portion of a substrate against a substrate holder, a clamp ring elevating mechanism for elevating and lowering the clamp ring, and a substrate thruster for raising and lowering a push-up pin inserted through the substrate holder. A plasma processing apparatus comprising a mechanism, wherein the clamp ring elevating mechanism and the substrate lifting mechanism are driven by a common drive motor and operate in synchronization. 2. The clamp ring lifting mechanism is connected to the driving motor by a first belt pulley mechanism. The substrate lifting mechanism includes a lifting plate to which a lifting pin is fixed, and a lifting plate fixed to the lifting plate. A cam follower is provided, and a cylindrical groove cam having a cam groove with which the cam follower is engaged is provided. The cylindrical groove cam is connected to the driving motor by a second belt pulley mechanism. The plasma processing apparatus according to claim 1. 3. The cylindrical groove cam has two cam grooves of the same shape and formed symmetrically, and two cam followers are symmetrically arranged on the push-up plate with respect to the cylindrical groove cam. 3. The plasma processing apparatus according to claim 2, wherein each of the cam followers is engaged with a corresponding cam groove. 4. The controller according to claim 1, further comprising a controller that detects an output torque of the driving motor from an output signal of a driver of the driving motor, and controls rotation of the driving motor based on the detected output torque. 4. The plasma processing apparatus according to any one of 3. 5. The controller according to claim 4, wherein the controller causes the drive motor to repeat forward and reverse rotation when the output torque exceeds a predetermined value, and causes the push-up shaft to repeatedly push up the substrate. 3. The plasma processing apparatus according to 1.