JP2004111468A - Clamping device, etching apparatus, and clamp cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the effect of a wafer-depressing clamp on etching characteristics. <P>SOLUTION: A wafer clamp 9 has a built-in heater 8 for heating itself, and a thermistor 11 is attached to the tip of its claw 9a for sensing the temperature of the wafer clamp 9 or of a wafer W. A temperature controller 15 is provided, which, based on the on/off control of an RF power source 13 by an RF power controller 14, controls the temperature of a heater 10 and, based on the surface temperature of the wafer W determined by the thermistor 11, controls the temperature of the heater 8. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a clamp device, an etching device, and a method of cleaning a clamp, and is particularly suitable when applied to a case where peeling of a reactive substance attached to the clamp is suppressed.
[0002]
[Prior art]
In a conventional dry etching apparatus, there is a method in which a wafer is fixed in the dry etching apparatus by holding the wafer with a clamp.
Here, the temperature of the clamp was kept at room temperature during the etching standby, and during the etching process, the temperature cycle was repeatedly increased to about 100 to 300 ° C. due to the influence of plasma or the like.
[0003]
[Problems to be solved by the invention]
However, when an etching process is performed in a dry etching apparatus, a reaction product adheres to the clamp.
Then, when the clamp repeats the temperature cycle, the reaction product adhered to the clamp repeatedly expands and contracts, and the reaction product cracks, and the reaction product peels off from the clamp.
[0004]
If the reaction product is peeled off from the clamp during the etching process, the reaction product falls on the wafer, causing a pattern short due to poor etching, the occurrence of corrosion due to Al etching, and the like, and the quality of the semiconductor product is deteriorated. was there.
Also, during the etching process, the clamp was placed near the wafer, and the temperature cycle of the clamp had a great effect on the etching characteristics.
[0005]
That is, when the temperature of the clamp is high, the reaction product is unlikely to adhere to the clamp, and when the temperature of the clamp is low, the reaction product is likely to adhere to the clamp.
For this reason, there is a problem that the amount of the reaction gas near the wafer during the etching process fluctuates due to the temperature cycle of the clamp, and the etching characteristics become unstable. Therefore, an object of the present invention is to provide a clamp device, an etching device, and a clamp cleaning method that can suppress the influence of the clamp on etching characteristics.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, according to the clamp device of claim 1, a pressing unit that presses a wafer, a heating unit built in the pressing unit, and a temperature detecting unit provided in the pressing unit are provided. It is characterized by having.
This makes it possible to control the temperature of the clamp device while monitoring the temperature of the clamp device, so that the temperature of the clamp device can be controlled without being affected by the plasma generation state, the temperature of the upper and lower electrodes, the temperature of the chamber wall, and the like. It can be stabilized.
[0007]
For this reason, it is possible to reduce the temperature fluctuation of the clamp device, to suppress the separation of the reaction product, to stabilize the amount of the reaction product attached, and to stabilize the quality of the semiconductor product. It is possible to do.
Further, according to the clamp device according to claim 2, a claw member for holding the wafer, a ring-shaped member for supporting the claw member around the wafer, a heating unit built in the ring-shaped member, and the claw member And a temperature detecting means provided at the tip of the device.
[0008]
This makes it possible to control the temperature of the clamp device while suppressing direct exposure of the heating means to the plasma, and to perform the etching process while monitoring the temperature of the wafer surface.
For this reason, it becomes possible to reduce the temperature fluctuation and suppress the separation of the reaction product, and to stabilize the amount of the reaction product attached, thereby stabilizing the quality of the semiconductor product. It becomes possible.
[0009]
Further, according to the etching apparatus of claim 3, a chamber for isolating the wafer, plasma generating means for generating plasma in the chamber, clamp means for holding a wafer placed in the chamber, and the clamp means And a temperature control means for controlling the temperature of the heating means based on the generation state of the plasma generated in the chamber.
[0010]
This makes it possible to heat the clamp means by the heating means when the plasma is off and raise the temperature of the clamp means, and to turn off the heating means when the plasma is on. As a result, the temperature of the clamping means can be kept constant.
This makes it possible to stabilize the temperature of the clamping means without being affected by the state of plasma generation, and to reduce the influence of the temperature cycle of the clamping means on the etching characteristics, thereby stabilizing the quality of semiconductor products. It is possible to do.
[0011]
According to the etching apparatus of the fourth aspect, the chamber for isolating the wafer, the plasma generating means for generating plasma in the chamber, the clamp means for holding down the wafer placed in the chamber, and the clamp means And a temperature control means for controlling the temperature of the heating means based on a temperature detection result provided by the temperature detection means. I do.
[0012]
This makes it possible to control the temperature of the clamp device while monitoring the temperature of the clamp device, and to stabilize the temperature of the clamp device without depending on the processing conditions, thereby stabilizing the quality of semiconductor products. It becomes possible.
According to a fifth aspect of the present invention, there is provided a method for cleaning a clamp, wherein a reaction product attached to a clamp for holding a wafer is removed by performing a dry etching process in a dry etching apparatus.
[0013]
Thus, it is possible to remove the reaction products attached to the clamp while the clamp is mounted in the dry etching apparatus, and it is possible to reduce the generation of particles from the clamp while suppressing a decrease in throughput.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a clamp device and an etching device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing a schematic configuration of the etching apparatus according to the first embodiment of the present invention.
[0015]
In FIG. 1, a chamber 1 is provided with a gas introduction pipe 2 for introducing an etching gas and a gas exhaust pipe 3 for discharging a reaction gas.
The chamber 1 is provided with an upper electrode 4 and a lower electrode 7 for generating plasma P1 in the chamber 1. The upper electrode 4 is connected to an RF power supply 13, and the lower electrode 7 is connected via an insulating layer 6. The heater 8 that is installed on the wafer mounting table 5 and heats the wafer W is built in the lower electrode 7.
[0016]
Further, a ring-shaped wafer clamp 9 is provided on the lower electrode 7 via a clamp lifter 12 that moves the wafer clamp 9 up and down. The wafer clamp 9 is provided with a claw member 9a for pressing the wafer from above by point contact. Have been.
The wafer clamp 9 has a built-in heater 8 for heating the wafer clamp 9, and a thermistor 11 for detecting the temperature of the wafer clamp 9 or the wafer W is attached to the tip of the claw member 9 a.
[0017]
FIG. 2A is a plan view showing a schematic configuration of the wafer clamp of FIG. 1, and FIG. 2B is a cross-sectional view taken along line AA of FIG. 2A.
2, the wafer clamp 9 is formed in a ring shape corresponding to the outer periphery of the wafer W, and a claw member 9a is provided on the inner periphery of the wafer clamp 9 to press the outer periphery of the wafer W by point contact. .
[0018]
In addition, the wafer clamp 9 and the claw member 9a can be formed of an insulator such as a ceramic, for example.
The wafer clamp 9 has a built-in heater 8 for heating the wafer clamp 9. For example, the wafer clamp 9 may have a sandwich structure in which the heater 8 is sandwiched by the wafer clamp 9.
[0019]
Further, a temperature detecting means for detecting the temperature of the wafer clamp 9 or the wafer W is provided at the tip of the claw member 9a. As the temperature detecting means, for example, a thermistor 11 or the like can be used.
In FIG. 1, the RF power supply 13 is connected to an RF power supply control device 14 for performing on / off control of the RF power supply 13, and the temperature control device 15 includes heaters 8 and 10, a thermistor 11, and an RF power supply control device. 14.
[0020]
Then, the temperature controller 15 controls the temperature of the heater 10 based on the on / off control of the RF power supply 13 by the RF power supply controller 14, and based on the detection result of the surface temperature of the wafer W by the thermistor 11. The temperature of the heater 8 is controlled.
FIG. 3 is a timing chart showing the on / off operation of the heater 10 in the etching apparatus of FIG.
[0021]
In FIG. 3, when the RF power supply 13 is off, the temperature control device 15 turns on the heater 10 to heat the wafer clamp 9 and raise the temperature of the wafer clamp 9.
Then, when the RF power supply 13 is turned on and the plasma P1 is generated in the chamber 1, the temperature controller 15 turns off the heater 10 to stop the heating of the wafer clamp 9 by the heater 10, and the wafer P Is maintained (t1).
[0022]
Further, when the etching process of the wafer W is completed and the RF power supply 13 is turned off again, the temperature control device 15 turns on the heater 10, heats the wafer clamp 9, and maintains the temperature of the wafer clamp 9 (t2). .
This makes it possible to stabilize the temperature of the wafer clamp 9 without being affected by the generation state of the plasma P1.
[0023]
For this reason, it is possible to suppress the expansion and contraction of the reaction product attached to the wafer clamp 9, to suppress the separation of the reaction product attached to the wafer clamp 9, and to suppress the reaction product attached to the wafer clamp 9. Of the semiconductor product can be stabilized, and the quality of the semiconductor product can be stabilized.
The temperature of the heater 10 can be set at any time without affecting the etching characteristics of the wafer W and within a range that does not cause scorching of the resist formed on the wafer W. The temperature can always be set to 100 to 200 ° C.
[0024]
FIG. 4 is a sectional view showing a schematic configuration of an etching apparatus according to the second embodiment of the present invention.
In FIG. 4, a chamber 21 is provided with a gas introduction pipe 22 for introducing an etching gas and a gas exhaust pipe 23 for discharging a reaction gas.
The chamber 21 is provided with an upper electrode 24 and a lower electrode 27 for generating plasma P2 in the chamber 21. The upper electrode 24 is connected to an RF power supply 31 and the lower electrode 27 is connected via an insulating layer 26. The heater 28 is installed on the wafer mounting table 25 and heats the wafer W inside the lower electrode 27.
[0025]
Further, on the lower electrode 27, a ring-shaped wafer clamp 29 is provided via a clamp lifter 30 for raising and lowering the wafer clamp 29. The wafer clamp 29 is provided with a claw member 29a for pressing the wafer from above by point contact. Have been.
When reactive products adhere to the wafer clamp 29 by the etching process in the chamber 21, an etching gas for removing the reactive products attached to the wafer clamp 29 is removed in the chamber 21 with the wafer W removed. To be introduced.
[0026]
Then, when the RF power supply 31 is turned on, the plasma P2 is generated in the chamber 21, and the reactive products attached to the wafer clamp 29 are removed by etching. As a result, it is possible to remove reaction products attached to the wafer clamp 29 while the wafer clamp 29 is mounted in the dry etching apparatus, and to suppress the generation of particles from the wafer clamp 29 while suppressing a decrease in throughput. Can be reduced.
[0027]
【The invention's effect】
As described above, according to the present invention, by controlling the temperature of the clamp device while monitoring the temperature of the lamp device, it is possible to stabilize the temperature of the clamp device and suppress the separation of the reaction product. And the amount of reaction products attached can be stabilized, and the quality of semiconductor products can be stabilized.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a schematic configuration of an etching apparatus according to a first embodiment of the present invention.
2 (a) is a plan view showing a schematic configuration of the wafer clamp of FIG. 1, and FIG. 2 (b) is a cross-sectional view taken along line AA of FIG. 2 (a).
FIG. 3 is a timing chart showing ON / OFF operations of a heater in the etching apparatus of FIG. 1;
FIG. 4 is a sectional view illustrating a schematic configuration of an etching apparatus according to a second embodiment of the present invention.
[Explanation of symbols]
1, 21 chamber, 2, 22 gas introduction pipe, 3, 23 gas exhaust pipe, 4, 24 upper electrode, 5, 25 wafer mounting table, 6, 26 insulating layer, 7, 27 lower electrode, 8, 10, 28 heater , 9, 29 Wafer clamp, 11 Thermistor, 12, 30 Clamp lifter, 13 RF power supply, 14, 31 RF power control device, 15 Temperature control device, 9a, 29a Claw member, P1, P2 Plasma

Claims (5)

Holding means for holding the wafer;
Heating means built into the holding means,
A clamp device comprising: a temperature detection unit provided in the holding unit. A claw member for holding the wafer,
A ring-shaped member supporting the claw member around the wafer;
Heating means built into the ring-shaped member,
A clamp device comprising: a temperature detector provided at a tip of the claw member. A chamber for isolating the wafer;
Plasma generating means for generating plasma in the chamber;
Clamping means for holding a wafer placed in the chamber;
Heating means built into the clamping means,
An etching apparatus comprising: a temperature control unit that controls a temperature of the heating unit based on a generation state of plasma generated in the chamber. A chamber for isolating the wafer;
Plasma generating means for generating plasma in the chamber;
Clamping means for holding a wafer placed in the chamber;
Heating means built into the clamping means,
Temperature detection means provided in the clamp means,
An etching apparatus comprising: a temperature control unit that controls the temperature of the heating unit based on a temperature detection result by the temperature detection unit. A method of cleaning a clamp, comprising removing a reaction product attached to a clamp for holding a wafer by performing a dry etching process in a dry etching apparatus.

Images