JP4308034B2 - Dry etching equipment - Google Patents

Description

  The present invention relates to a dry etching apparatus that performs etching on a wafer by generating plasma in order to manufacture a semiconductor element or the like.

2. Description of the Related Art Conventionally, in order to manufacture a semiconductor element or the like, a dry etching apparatus that generates plasma and performs etching on a wafer has been provided (see, for example, Patent Document 1).
Such a dry etching apparatus includes an etching unit that performs etching by generating plasma in an etching chamber, and a load lock unit that transports a wafer into and out of the etching chamber.

FIG. 7 is a block diagram showing a main configuration of the conventional dry etching apparatus.
The above-described etching unit 800 includes a box 801 constituting an etching chamber, a lower electrode 802 disposed in the etching chamber, a solid coil 803, a high-frequency power source 804 that applies a high-frequency voltage to the solid coil 803, and a lower electrode. A high frequency power source 805 that applies a high frequency voltage to 802, a DC power source 806 that applies a DC voltage to the lower electrode 802, a plurality of push pins 807 for moving the wafer 1 up and down on the lower electrode 802, and a plurality of push pins 807 And a shaft moving mechanism for moving the vertical shaft 808 in the vertical direction. The shaft moving mechanism includes a support column 809 projecting from the lower portion of the box body 801, and an elevating fork 810 that is pivotally attached to the support column 809 with the tip end of the support column 809 serving as a fulcrum.

When the high frequency power source 804 applies a high frequency voltage to the three-dimensional coil 803 and the high frequency power source 805 applies a high frequency voltage to the lower electrode 802, plasma is generated in the etching chamber, and the wafer placed on the upper surface of the lower electrode 802 by the plasma. 1 is etched. When the etching is finished, the high frequency power supplies 804 and 805 stop outputting.
Here, when etching is performed, the DC power source 806 applies a DC voltage to the lower electrode 802 to electrostatically attract the wafer 1 and the lower electrode 802. That is, when a DC voltage is applied to the lower electrode 802, electric charges accumulate on the upper surface side of the lower electrode 802, and the wafer 1 and the lower electrode 802 are attracted to each other by Coulomb force through the insulating film.

  On the other hand, the above-described load lock unit 900 includes a box body 901 that constitutes a load lock chamber, a load lock arm 902 that is installed in the load lock chamber and carries the wafer 1, and swings, expands, contracts, or retracts. An arm moving mechanism 903 for moving up and down, and a drive unit 904 including a motor for driving the arm moving mechanism 903 and the lifting / lowering fork 810 of the shaft moving mechanism are provided.

  Here, the drive unit 904 includes a Fisher arm 905 having a roller 905a at the tip. A roller 905a at one end of the fisher arm 905 is fitted in a groove 810a formed at one end of the lifting / lowering fork 810 of the shaft moving mechanism. For example, a roller 905a having a diameter of 16 mm is fitted into a groove 810a having a width of 17 mm. The other end of the lifting / lowering fork 810 is engaged with a groove fitting 812 attached to the vertical shaft 808.

  That is, the above-described driving unit 904 drives the arm moving mechanism 903 to move the load lock arm 902, thereby transferring the wafer 1 into the box body 801 of the etching unit 800 or the wafer in the box body 801. 1 and the like, and the Fischer arm 905 is rotated to rotate the lifting / lowering fork 810 with the tip of the support 809 as a fulcrum, and the vertical shaft 808 is moved in the vertical direction. By such movement of the vertical axis 808, the tip of the push-up pin 807 protrudes from the upper surface of the lower electrode 802 or is stored in the lower electrode 802.

Such a dry etching apparatus performs etching on the wafer 1 placed on the upper surface of the lower electrode 802 by moving the push-up pin 807 downward so that the tip of the push-up pin 807 is accommodated in the lower electrode 802. When carrying the wafer, the push-up pin 807 is moved upward so that the tip of the push-up pin 807 is about 35 mm above the upper surface of the lower electrode 802, and the wafer 1 is pushed up from the lower electrode 802 by that height. In this state, the load lock arm 902 is moved.
JP 2000-77389 A

  However, in the conventional dry etching apparatus, it is difficult to adjust the rotation angle of the Fischer arm 905 by the driving unit 904, and the height of the push pin 807 tip from the upper surface of the lower electrode 802 (push height) is the lowest. Even if it can be easily set to 0 mm and the maximum 35 mm, it is difficult to set to a low height therebetween. As a result, there is a problem in that it is not possible to appropriately neutralize the wafer 1 and the lower electrode 802.

  That is, even when the application of the DC voltage to the lower electrode 802 is stopped at the end of the etching process, the wafer 1 is kept electrostatically attracted to the lower electrode 802 by the charge remaining on the wafer 1 and the lower electrode 802. In such a case, if the wafer 1 is forcibly pulled away from the lower electrode 802 by pushing up the push-up pins 807, the wafer 1 may be damaged, or the position of the pushed-up wafer 1 may be shifted and the load lock arm An error occurs in scooping and transporting by 902. Therefore, in order to remove charges remaining on the wafer 1 and the lower electrode 802, a plasma is generated by applying a high frequency voltage to the lower electrode 802 and the solid coil 803 at a low output, and the wafer 1 is attached to the lower electrode 802 during the generation of the plasma. It is necessary to push it up by about 1 mm from the upper surface.

However, in the conventional dry etching apparatus, it is difficult to adjust the angle of the Fisher arm 905 so that the push-up height is set in two stages of 1 mm and 35 mm.
Therefore, the present invention has been made in view of such a problem, and an object of the present invention is to provide a dry etching apparatus that appropriately performs static elimination of a wafer.

  In order to achieve the above object, a dry etching apparatus according to the present invention is a dry etching apparatus that performs etching on a wafer by generating plasma, and includes a push-up pin that pushes up a wafer installed on an electrode, and one end side. A rotating fork in which a groove is formed and the other end moves by moving the push pin in the axial direction by rotating, and one end is fitted in the groove of the rotating fork with a gap, and the rotating fork The arm for rotating the rotating fork by pressing the peripheral portion of the groove and the one end side where the groove of the rotating fork is formed are pressed by the amount corresponding to the gap between the rotating fork and the arm. And a pressing device for rotating the rotating fork. For example, the pusher pushes the rotating fork to push the wafer up to a height of approximately 1 mm from the electrode, and the arm pushes the rotating fork to push the wafer from the electrode to approximately 35 mm. Push up to the height of. For example, the clearance between the rotating fork and the arm is approximately 1.5 mm.

  As a result, since the pressing device rotates the rotating fork by the gap between the rotating fork and the arm, the push-up pin can be moved by that amount to push the wafer from the electrode at a low height. In other words, the push-up pin pushes up the wafer from the electrode by the turning of the turning fork by the arm, but the height of the push-up by the operation of the arm cannot be adjusted to be as low as 1 mm, for example. However, the wafer can be pushed up at a low height by rotating the rotating fork by the gap of the pressing device as described above. As a result, after the etching is completed, the wafer can be pushed up from the electrode a little and the charge can be appropriately removed.

  The dry etching apparatus further includes control means for controlling the movement of the arm and the presser, and the control means causes the presser to press the rotating fork when plasma is generated. The wafer is pushed up from the electrode, the charge accumulated in the wafer is neutralized, and the arm is further pushed up without placing it on the electrode by pressing the rotating fork against the arm in the pushed up state. It is good as a feature.

  As a result, if the height of the wafer being pushed up by the arm is set to a height required for carrying the wafer, the wafer after charge removal is pushed up to the height for conveyance without being placed on the electrode. The occurrence of errors can be prevented. In other words, even if the wafer is pushed up during the generation of the plasma and the charge is removed, the charge accumulated on the wafer is not completely removed.If the wafer is placed on the electrode, the wafer is electrostatically attracted to the electrode. When the push-up pins are pushed up to the height for conveyance, the wafer pushed up by the electrostatic adsorption is displaced and a conveyance error occurs. However, as described above, since the wafer after charge removal is pushed up to the height for conveyance without being placed on the electrode, the occurrence of a conveyance error can be prevented.

  The present invention can be realized not only as a dry etching apparatus as described above but also as a method of pushing up a wafer by which the dry etching apparatus pushes up a wafer, a program based on the method, and a storage medium for storing the program Can also be realized.

  The dry etching apparatus of the present invention has an operational effect that the wafer can be pushed up from the electrode a little and the charge can be appropriately removed.

Hereinafter, a dry etching apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic internal configuration of a dry etching apparatus in the present embodiment.
The dry etching apparatus in the present embodiment appropriately performs static elimination of the wafer 1, and includes an unprocessed cassette 301 in which the unprocessed wafer 1 is loaded, and an etching unit 100 that performs an etching process on the wafer 1 in the room. The rinsing unit 300 that performs the rinsing process on the wafer 1 in the room, the ashing unit 400 that performs the ashing process on the wafer 1 in the room, and the etching unit 100, the rinsing unit 300, and the ashing unit 400. A load lock unit 200 having a load lock arm 202 for carrying the wafer 1, a processed cassette 302 loaded with the wafer 1 subjected to etching and rinsing, a load lock unit 200, an unprocessed cassette 301, and Transfer of wafer 1 to processed cassette 302 A handling portion 303 having a handling arm 304 to perform, and a control unit 305 for controlling the respective units, untreated cassettes 301 and processed cassette 302,.

  In such a dry etching apparatus, first, the handling unit 303 takes out one wafer 1 loaded in the unprocessed cassette 301 by the handling arm 304 and transports the wafer 1 into the load lock unit 200. The load lock arm 202 in the room of the load lock unit 200 further carries the wafer 1 conveyed by the handling unit 303 into the room of the etching unit 100 and places the wafer 1 in a predetermined place. The etching unit 100 generates plasma and performs an etching process on the installed wafer 1.

  After the etching process is completed, the load lock arm 202 of the load lock unit 200 takes out the etched wafer 1 from the chamber of the etching unit 100 and conveys the wafer 1 into the chamber of the rinse unit 300 or the ashing unit 400. Install in place. The rinsing unit 300 performs a rinsing process with pure water or a chemical solution on the wafer 1. The ashing unit 400 performs an ashing process on the wafer 1 with plasma. After the rinsing process is completed, the load lock arm 202 of the load lock unit 200 takes out the rinsed or ashed wafer 1 from the rinse unit 300 or the ashing unit 400, and handles the wafer 1 in the handling unit 303. Deliver to 304. The handling arm 303 loads the transferred wafer 1 into the processed cassette 302.

FIG. 2 is a configuration diagram showing the configuration of the etching unit 100 and the load lock unit 200.
The etching unit 100 includes a box 101 constituting an etching chamber, a lower electrode 102 disposed in the etching chamber, a three-dimensional coil 103, a high-frequency power source 104 that applies a high-frequency voltage to the three-dimensional coil 103, and a lower electrode 102 A high-frequency power source 105 that applies a high-frequency voltage, a DC power source 106 that applies a DC voltage to the lower electrode 102, a plurality of push-up pins 107 for raising and lowering the wafer 1 on the lower electrode 102, and a base of the plurality of push-up pins 107 And a shaft moving mechanism for moving the vertical shaft 108 in the vertical direction.

The shaft moving mechanism of the present embodiment includes a support column 109 projecting from the lower portion of the box body 101, a lifting / lowering fork 110 rotatably attached to the support column 109 with the tip of the support column 109 as a fulcrum, And an actuator 111 that presses the elevating fork 110 by extending and contracting.
On the other hand, the load lock unit 200 includes a box body 201 constituting a load lock chamber, a load lock arm 202 installed in the load lock chamber, an arm moving mechanism 203 for turning or extending and retracting the load lock arm 202, And a drive unit 204 including a motor for driving the arm moving mechanism 203 and the lifting / lowering fork 110 of the shaft moving mechanism.

  Here, the drive unit 204 includes a fisher arm 205 having a roller 205a at the tip. A roller 205a at one end of the fisher arm 205 is fitted into a groove 110a formed at one end of the lifting / lowering fork 110 of the shaft moving mechanism. The other end of the lifting / lowering fork 110 is engaged with a groove fitting 112 attached to the vertical shaft 108.

FIG. 3 is an explanatory diagram for explaining a state in which the roller 205a of the fisher arm 205 is fitted in the groove 110a of the elevating fork 110.
The width of the groove 110a of the lifting / lowering fork 110 is sufficiently larger than the diameter of the roller 205a of the fisher arm 205, and even if the roller 205a is fitted in the groove 110a, a gap is formed in the groove 110a in the width direction. For example, a roller 205a having a diameter of 16 mm is fitted into a groove 110a having a width of 18 mm. At this time, there is a gap (upper gap) of about 1.5 mm between the upper peripheral wall of the groove 110a of the lifting / lowering fork 110 and the roller 205a, and the lower peripheral wall of the groove 110a of the lifting / lowering fork 110 and the roller 205a. There is a gap (lower gap) of about 0.5 mm between and a total of about 2 mm. The lower gap (0.5 mm) is used for smoothly inserting and removing the roller 205a of the fisher arm 205 from the groove 110a of the lifting / lowering fork 110.

The above-described actuator 111 presses one end where the groove 110a of the lifting / lowering fork 110 is formed downward from above, and the upper peripheral wall of the groove 110a of the lifting / lowering fork 110 and the roller 205a of the fisher arm 205 are pressed. One end is pushed down a certain amount within the range of the upper gap.
As a result, as shown in FIG. 2, the lifting / lowering fork 110 rotates by a minute angle with the tip end of the support column 109 as a fulcrum, and pushes up the groove fitting 112 attached to the vertical shaft 108. As a result, the vertical shaft 108 and the push-up pin 107 move upward, and the tip of the push-up pin 107 protrudes from the upper surface of the lower electrode 102 by about 1 mm.

  Further, the driving unit 204 described above drives the arm moving mechanism 203 to move the load lock arm 202, thereby transferring the wafer 1 into the box body 101 of the etching unit 100, or a wafer in the box body 101. 1 is transported outside. Further, the drive unit 204 rotates the fisher arm 205 to press the lifting / lowering fork 110 with the roller 205a to rotate the tip of the support column 109 about the fulcrum, thereby moving the vertical shaft 108 in the vertical direction. As a result, the drive unit 204 causes the tip of the push-up pin 107 to protrude from the upper surface of the lower electrode 102 by about 35 mm or to be accommodated in the lower electrode 102.

FIG. 4 is an explanatory diagram for explaining the operation of projecting the tip of the push-up pin 107 by about 35 mm from the upper surface of the lower electrode 102.
The drive unit 204 rotates the Fischer arm 205 to bring the roller 205a of the Fischer arm 205 into contact with the lower peripheral wall of the groove 110a of the lifting / lowering fork 110, and causes the roller 205a to push the peripheral wall downward. As a result, the lifting / lowering fork 110 pivots greatly with the tip of the support column 109 as a fulcrum and pushes up the groove fitting 112 attached to the vertical shaft 108, and the push-up pin 107 is about a height above the upper surface of the lower electrode 102. Projects to 35mm. As a result, the wafer 1 is pushed up by the height from the upper surface of the lower electrode 102.

With respect to such a dry etching apparatus, operations during etching, charge removal, and wafer transfer after charge removal will be described below.
First, when etching is performed, the control unit 305 turns on the DC power source 106 and applies a DC voltage to the lower electrode 102 to electrostatically attract the wafer 1 and the lower electrode 102. That is, when a DC voltage is applied to the lower electrode 102, electric charges are accumulated on the upper surface side of the lower electrode 102, and the wafer 1 and the lower electrode 102 are attracted to each other by Coulomb force through the insulating film.

  Then, in this state of electrostatic adsorption, the control unit 305 turns on the high frequency power source 104 to apply a high frequency voltage of about 13.56 MHz to the solid coil 103, and further turns on the high frequency power source 105 to about 13.56 MHz. Is applied to the lower electrode 102 to generate plasma in the etching chamber to etch the surface of the wafer 1. When the etching is completed, the control unit 305 turns off the high-frequency power sources 104 and 105 and also turns off the DC power source 106.

Next, when the charge remaining on the wafer 1 and the lower electrode 102 is removed, the control unit 305 turns on the high-frequency power sources 104 and 105 again to apply a high-frequency voltage to the three-dimensional coil 103 and the lower electrode 102 at a low output. Generate plasma. While the plasma is being generated, the controller 305 causes the actuator 111 to press the lifting / lowering fork 110 so that the push-up pin 107 protrudes from the upper surface of the lower electrode 102 by about 1 mm and is placed on the lower electrode 102. The wafer 1 that has been hit is pushed up. (Hereinafter, the height of the wafer pushed up for such charge removal is referred to as charge removal height.)
When the static elimination is completed, the control unit 305 turns off the high-frequency power sources 104 and 105 and rotates the fisher arm 205 to the drive unit 204 to push the wafer 1 by about 35 mm. (Hereafter, the height of the wafer pushed up in this way is referred to as the transfer height)
When the wafer 1 is pushed up to the transfer height, the control unit 305 causes the drive unit 204 to drive the arm moving mechanism 203 to move the load lock arm 202 to the etching chamber. The wafer 1 at the transfer height is received by the load lock arm 202 and transferred to the load lock chamber.

FIG. 5 is an explanatory diagram for explaining temporal transitions between the outputs of the high-frequency power sources 104 and 105 and the height (push-up height) from the lower electrode 102 of the wafer 1.
The control unit 305, for example, turns on the DC power source 106 at time t1 to electrostatically attract the wafer 1 to the lower electrode 102 and raises the output of the high frequency power sources 104 and 105 to generate plasma and start etching. To do. When the etching is started, the control unit 305 gradually decreases the outputs of the high frequency power sources 104 and 105, stops the outputs at time t2, and ends the etching. Thereafter, the control unit 305 turns off the DC power source 106 at time t3.

Next, at time t4, the control unit 305 generates a high-frequency voltage from the high-frequency power sources 104 and 105 at a low output, and starts neutralizing the wafer 1 and the lower electrode 102. At time t5 during the static elimination, the control unit 305 controls the actuator 111 so that the push-up height is about 1 mm of the static elimination height. At time t6, the control unit 305 turns off the high frequency power supplies 104 and 105.
Thereafter, at time t7, the control unit 305 controls the driving unit 204 to rotate the Fischer arm 205 so that the pushed-up wafer 1 is not placed on the lower electrode 102, and the pushed-up height is set to about 1 mm of the static elimination height. The conveyance height is changed to about 35 mm. Then, the control unit 305 controls the drive unit 204 at time t8 to drive the arm moving mechanism 203, thereby causing the load lock arm 202 to start transporting the wafer 1.

FIG. 6 is a flowchart showing a series of operations from etching to transfer of the wafer 1.
First, the control unit 305 performs etching by generating plasma by turning on the high-frequency power sources 104 and 105 and the DC power source 106 (step S100), and again outputs the low-frequency power sources 104 and 105 that are turned off at the end of the etching to a low output. At step S102, static electricity is started by turning on. Then, the control unit 305 pushes up the wafer 1 from the lower electrode 102 by 1 mm of the static elimination height by controlling the driving unit 204 (step S104).

  Next, the control unit 305 ends the static elimination by turning off the high-frequency power sources 104 and 105 (step S106), and pushes the wafer 1 from the static elimination height of 1 mm to the conveyance height of 35 mm (step S108). Then, the control unit 305 controls the driving unit 204 to move the load lock arm 202, and transports the wafer 1 from the etching chamber to the load lock chamber (step S110).

  The dry etching apparatus of the present invention has an effect that the charge removal of the wafer can be appropriately performed, and can be applied to the electronic equipment manufacturing industry and the like.

It is a block diagram which shows the schematic internal structure of the dry etching apparatus in this Embodiment. It is a block diagram which shows the structure of the etching part same as the above, and a load lock part. It is explanatory drawing for demonstrating the state by which the roller of the Fisher arm is engage | inserted in the groove | channel of the raising / lowering fork same as the above. It is explanatory drawing for demonstrating the operation | movement which projects the front-end | tip of a raising pin same as the above from the upper surface of a lower electrode only 35 mm. It is explanatory drawing for demonstrating temporal transition with the output of the high frequency power supply same as the above, and the height from the lower electrode 102 of the front-end | tip of a push-up pin. It is a flowchart which shows a series of operation | movement from the etching same as the above to conveyance of a wafer. It is a block diagram which shows the principal part structure of the conventional dry etching apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 100 Etching part 102 Lower electrode 103 Solid coil 104,105 High frequency power supply 106 DC power supply 107 Push-up pin 108 Vertical axis 110 Lifting fork 110a Groove 111 Actuator 200 Load lock chamber 200
202 Arm 203 Arm moving mechanism 204 Drive unit 205 Fisher arm 205a Roller

Claims (13)

A dry etching apparatus that performs etching on a wafer by generating plasma,
A push-up pin that pushes up the wafer installed on the electrode; and
A rotating fork in which a groove is formed on one end side and the other end side moves the push pin along the axial direction by rotating;
One end is fitted to the groove of the rotating fork with a gap, and an arm that rotates the rotating fork by pressing the groove periphery of the rotating fork;
Dry etching, comprising: a pressing device that rotates the rotating fork by an amount corresponding to a gap between the rotating fork and an arm by pressing one end side where the groove of the rotating fork is formed. apparatus. The dry etching apparatus according to claim 1, wherein the pressing device pushes up the wafer from an electrode to a charge removal height by pressing the rotating fork. The dry etching apparatus according to claim 2, wherein the pressing device pushes up the wafer to a height of about 1 mm as the static elimination height. The dry etching apparatus according to any one of claims 1 to 3, wherein the arm pushes up the wafer from the electrode to a transfer height by pressing the rotating fork. The dry etching apparatus according to claim 4, wherein the arm pushes up the wafer to a height of about 35 mm as the transfer height. The dry etching apparatus according to any one of claims 1 to 5, wherein a gap between the rotating fork and the arm is approximately 1.5 mm. The dry etching apparatus further includes:
Control means for controlling the movement of the arm and the pusher;
The control means includes
When plasma is generated, the rotating fork is pressed by the pressing device to push up the wafer from the electrode to remove charges accumulated on the wafer, and in the pushed-up state, the rotating fork is rotated to the arm. The dry etching apparatus according to any one of claims 1 to 6, wherein the wafer is further pushed up without being placed on an electrode by pressing a moving fork. A dry etching apparatus that performs etching on a wafer by generating plasma is a method of pushing up a wafer that pushes up a wafer installed on an electrode after completion of etching,
The dry etching apparatus has a push-up pin that pushes up a wafer installed on an electrode, a groove that is formed on one end side, a turning fork that moves the push-up pin along the axial direction on the other end side by turning, and One end is fitted into the groove of the rotating fork with a gap, and an arm that rotates the rotating fork by pressing the peripheral portion of the groove of the rotating fork and a groove of the rotating fork are formed. A pressing device that rotates the rotating fork by an amount corresponding to a gap between the rotating fork and the arm by pressing the one end side;
The method of pushing up the wafer is as follows:
A first push-up step in which the pusher pushes the rotating fork to push the wafer out of the electrode when plasma is generated in order to remove charges accumulated in the wafer;
And a second push-up step in which the arm pushes the rotating fork and pushes the wafer further without placing it on the electrode in a state where the wafer is pushed up by the first push-up step. How to push up. The method of pushing up a wafer according to claim 8, wherein, in the first pushing-up step, the wafer is pushed up from the electrode by a static elimination height. The method of pushing up a wafer according to claim 9, wherein in the first pushing-up step, the wafer is pushed up by a height of about 1 mm as the static elimination height. The method of pushing up a wafer according to any one of claims 8 to 10, wherein, in the second pushing-up step, the wafer is pushed up from the electrode by a conveyance height. The method of pushing up a wafer according to claim 11, wherein, in the second pushing-up step, the wafer is pushed up by a height of about 35 mm as the transfer height.   The program which makes a computer perform the step contained in the pushing-up method of the wafer of any one of Claims 8-10.

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