PLASMA ETCHING APPARATUS AND PLASMA ETCHING METHOD

• US 20120132617A1
• Filed: 08/05/2010
• Published: 05/31/2012
• Est. Priority Date: 08/06/2009
• Status: Abandoned Application

• Current Assignee: Shibaura Mechatronics Corporation
• Original Assignee: Shibaura Mechatronics Corporation
• Inventors: MATSUSHIMA, Daisuke
• Application Number:
  US13/389,181
• Publication Number:
  US 20120132617A1
• Time in Patent Office: Days
• US Class Current: 216/60
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01J 37/32972 Spectral analysis
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32

Abstract

A plasma etching apparatus includes a processing container, a depressurization unit, a placement unit, a discharge tube, an introduction waveguide tube, a gas supply unit, a transport tube, a detection window, a coherent light detection unit, and a control unit. The control unit is configured to detect an end point of etching based on an output from the coherent light detection unit. The control unit is configured to use an output from the light receiving devices of a detection region of the coherent light detection unit to extract an output of the light receiving device of a portion of the detection region corresponding to an etching portion to detect the end point of the etching based on an intensity of the coherent light determined from the output of the light receiving device of the portion of the detection region corresponding to the etching portion.

Claims

1. A plasma etching apparatus, comprising:

a processing container capable of maintaining an atmosphere depressurized below atmospheric pressure;

a depressurization unit configured to depressurize an interior of the processing container to a prescribed pressure;

a placement unit provided in the interior of the processing container, the placement unit being configured to place a processing object;

a discharge tube provided at a position isolated from the processing container, the discharge tube having a region in an interior of the discharge tube used to generate plasma;

an introduction waveguide tube configured to cause microwaves radiated from a microwave production unit to propagate to introduce the microwaves to the region used to generate the plasma;

a gas supply unit configured to supply a process gas to the region used to generate the plasma;

a transport tube configured to link the discharge tube to the processing container;

a detection window provided in a wall surface of the processing container, the detection window being configured to transmit light;

a coherent light detection unit including a plurality of light receiving devices in a light reception surface configured to receive coherent light emitted from a surface of a processing object placed in the placement unit; and

a control unit configured to detect an end point of etching based on an output from the coherent light detection unit,

the control unit being configured to use an output from the light receiving devices of a detection region of the coherent light detection unit to extract an output of the light receiving device of a portion of the detection region corresponding to an etching portion to detect the end point of the etching based on an intensity of the coherent light determined from the output of the light receiving device of the portion of the detection region corresponding to the etching portion.

5. The plasma etching apparatus according to claim 1, wherein the control unit is configured to use a region having a large fluctuation amount of the intensity of the coherent light as a detection object to detect the end point of the etching based on an average of the intensity of the coherent light of the region.

2. A plasma etching apparatus, comprising:

a processing container capable of maintaining an atmosphere depressurized below atmospheric pressure, the processing container having a region in an interior of the processing container used to generate plasma;

a depressurization unit configured to depressurize the interior of the processing container to a prescribed pressure;

a placement unit provided in the interior of the processing container, the placement unit being configured to place a processing object;

a plasma generation unit configured to generate the plasma by supplying electromagnetic energy to the region used to generate the plasma;

a gas supply unit configured to supply a process gas to the region used to generate the plasma;

a detection window provided in a wall surface of the processing container, the detection window being configured to transmit light;

a coherent light detection unit including a plurality of light receiving devices in a light reception surface configured to receive coherent light emitted from a surface of a processing object placed in the placement unit; and

a control unit configured to detect an end point of etching based on an output from the coherent light detection unit,

the control unit being configured to use an output from the light receiving devices of a detection region of the coherent light detection unit to extract an output of the light receiving device of a portion of the detection region corresponding to an etching portion to detect the end point of the etching based on an intensity of the coherent light determined from the output of the light receiving device of the portion of the detection region corresponding to the etching portion.

6. The plasma etching apparatus according to claim 2, wherein the control unit is configured to use a region having a large fluctuation amount of the intensity of the coherent light as a detection object to detect the end point of the etching based on an average of the intensity of the coherent light of the region.

3. A plasma etching apparatus, comprising:

a processing container capable of maintaining an atmosphere depressurized below atmospheric pressure;

a depressurization unit configured to depressurize an interior of the processing container to a prescribed pressure;

a placement unit provided in the interior of the processing container, the placement unit being configured to place a processing object;

a discharge tube provided at a position isolated from the processing container, the discharge tube having a region in an interior of the discharge tube used to generate plasma;

an introduction waveguide tube configured to cause microwaves radiated from a microwave production unit to propagate to introduce the microwaves to the region used to generate the plasma;

a gas supply unit configured to supply a process gas to the region used to generate the plasma;

a transport tube configured to link the discharge tube to the processing container;

a detection window provided in a wall surface of the processing container, the detection window being configured to transmit light;

a light source configured to irradiate light via the detection window onto a surface of a processing object placed in the placement unit;

a coherent light detection unit including a plurality of light receiving devices in a light reception surface configured to receive coherent light emitted from the surface of the processing object placed in the placement unit; and

a control unit configured to detect an end point of etching based on an output from the coherent light detection unit,

the control unit being configured to use an output from the light receiving devices of a detection region of the coherent light detection unit to extract an output of the light receiving device of a portion of the detection region corresponding to an etching portion to detect the end point of the etching based on an intensity of the coherent light determined from the output of the light receiving device of the portion of the detection region corresponding to the etching portion.

7. The plasma etching apparatus according to claim 3, wherein the control unit is configured to use a region having a large fluctuation amount of the intensity of the coherent light as a detection object to detect the end point of the etching based on an average of the intensity of the coherent light of the region.

4. A plasma etching apparatus, comprising:

a processing container capable of maintaining an atmosphere depressurized below atmospheric pressure, the processing container having a region in an interior of the processing container used to generate plasma;

a depressurization unit configured to depressurize the interior of the processing container to a prescribed pressure;

a placement unit provided in the interior of the processing container, the placement unit being configured to place a processing object;

a plasma generation unit configured to generate the plasma by supplying electromagnetic energy to the region used to generate the plasma;

a gas supply unit configured to supply a process gas to the region used to generate the plasma;

a detection window provided in a wall surface of the processing container, the detection window being configured to transmit light;

a light source configured to irradiate light via the detection window onto a surface of a processing object placed in the placement unit;

a coherent light detection unit including a plurality of light receiving devices in a light reception surface configured to receive coherent light emitted from the surface of the processing object placed in the placement unit; and

a control unit configured to detect an end point of etching based on an output from the coherent light detection unit,

the control unit being configured to use an output from the light receiving devices of a detection region of the coherent light detection unit to extract an output of the light receiving device of a portion of the detection region corresponding to an etching portion to detect the end point of the etching based on an intensity of the coherent light determined from the output of the light receiving device of the portion of the detection region corresponding to the etching portion.

8. The plasma etching apparatus according to claim 4, wherein the control unit is configured to use a region having a large fluctuation amount of the intensity of the coherent light as a detection object to detect the end point of the etching based on an average of the intensity of the coherent light of the region.

9. A plasma etching method configured to generate plasma in an atmosphere depressurized below atmospheric pressure, produce plasma products by exciting a process gas supplied toward the plasma, and use the plasma products to perform etching of a processing object, the plasma etching method comprising:

detecting coherent light from the processing object by using a coherent light detection unit including a plurality of light receiving devices in a light reception surface; and

detecting an end point of etching based on an intensity of the coherent light by using an output from the light receiving devices of a detection region of the coherent light detection unit to extract an output of the light receiving device of a portion of the detection region corresponding to an etching portion, the intensity of the coherent light being determined from the output of the light receiving device of the portion of the detection region corresponding to the etching portion.

10. The plasma etching method according to claim 9, wherein the detecting of the end point of the etching includes using a region having a large fluctuation amount of the intensity of the coherent light as a detection object to detect the end point of the etching based on an average of the intensity of the coherent light of the region.