MICROWAVE PLASMA PROCESSING APPARATUS AND MICROWAVE SUPPLYING METHOD

• US 20150015139A1
• Filed: 07/09/2014
• Published: 01/15/2015
• Est. Priority Date: 07/10/2013
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: IWAO, Toshihiko, KANEKO, Kazushi, KAWAKAMI, Satoru
• Granted Patent: US 9,305,751 B2
• Time in Patent Office: Days
• US Class Current: 315/34
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32201 Generating means
• CPC Class Codes: H01J 37/32211 Means for coupling power to the plasma
• CPC Class Codes: H01J 37/3222 Antennas
• CPC Class Codes: H01J 37/32229 Waveguides
• CPC Class Codes: H01J 37/32238 Windows
• CPC Class Codes: H01J 37/32266 Means for controlling power transmitted to the plasma
• CPC Class Codes: H01J 37/32311 Circuits specially adapted for controlling the microwave discharge
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

A microwave plasma processing apparatus includes a processing space; a microwave generator which generates microwaves for generating a plasma; a distributor which distributes the microwaves to a plurality of waveguides; an antenna installed in a processing container to seal the processing space and to radiate microwaves distributed by the distributor, to the processing space; and a monitor unit configured to monitor a voltage of each of the plurality of waveguides. A control unit acquires a control value of a distribution ratio of the distributor, which corresponds to a difference between a voltage monitor value of the monitor unit and a predetermined voltage reference value, from a storage unit that stores the difference and the control value corresponding to each other. The control unit is also configured to control the distribution ratio of the distributor, based on the acquired control value.

Claims

1. A microwave plasma processing apparatus comprising:

a processing container configured to define a processing space;

a microwave generator configured to generate microwaves for generating plasma of a processing gas introduced into the processing space;

a distributor configured to distribute the microwaves to a plurality of waveguides;

an antenna installed in the processing container to seal the processing space, and to radiate the microwaves distributed to the plurality of waveguides by the distributor, to the processing space;

a monitor unit configured to monitor a voltage of each of the plurality of waveguides; and

a control unit configured to acquire a control value of a distribution ratio of the distributor, which corresponds to a difference between a monitor value of the voltage monitored by the monitor unit and a predetermined reference value of the voltage, from a storage unit that stores the difference and the control value of the distribution ratio of the distributor corresponding to the difference to correspond to each other, and to control the distribution ratio of the distributor, based on the acquired control value.

2. The microwave plasma processing apparatus of claim 1, further comprising:

a phase shifter installed in a specific waveguide of at least one of the plurality of waveguides to shift a phase of a voltage of the specific waveguide by a set shift amount,

wherein apart from the control of the distribution ratio of the distributor, the control unit properly controls the phase of the voltage of the specific waveguide and phases of voltages of waveguides other than the specific waveguide among the plurality of waveguides using the monitor value of the voltage monitored by the monitor unit so as to control the shift amount of the phase shifter such that the phases become inverse phases in a dielectric window below the antenna.

3. The microwave plasma processing apparatus of claim 1, further comprising:

a waveguide guiding the microwave generated by the microwave generator to the distributor; and

a tuner installed in the waveguide to match impedance at the microwave generator side and impedance of the antenna side.

4. The microwave plasma processing apparatus of claim 1, wherein the microwave plasma processing apparatus is provided with a plurality of sets of processing containers and the antennas,

the distributor distributes microwaves to the plurality of waveguides corresponding to the plurality of sets of processing containers and antennas, respectively,

the antenna radiates the microwaves distributed to each of the plurality of waveguides by the distributor to the processing space of the processing container combined with the antenna, and

the control unit controls the distribution ratio of the distributor based on the control value acquired from the storage unit.

5. The microwave plasma processing apparatus of claim 1, wherein the microwave plasma processing apparatus is provided with a plurality of distributors,

the plurality of distributors distribute the microwaves generated by the microwave generator to the plurality of waveguides stepwise sequentially,

the storage unit stores the difference and a control value of the distribution ratio of the distributor corresponding to the difference to correspond to each other, for each distributor, and

the control unit individually controls the distribution ratio of each of the plurality of distributors based on the control value acquired from the storage unit.

6. A microwave supplying method using a microwave plasma processing apparatus including a processing container configured to defined a processing space, a microwave generator configured to generate microwaves for generating plasma of a processing gas introduced into the processing space, a distributor configured to distribute the microwaves to a plurality of waveguides, and an antenna installed in the processing container so as to seal the processing space and to radiating, to the processing space, the microwaves distributed to the plurality of waveguides by the distributor, the method comprising:

monitoring a voltage of each of the plurality of waveguides;

acquiring a control value of a distribution ratio of the distributor corresponding to a difference between a monitor value of the monitored voltage and a predetermined reference value of the voltage from a storage unit which stores the difference and the control value of the distribution ratio of the distributor corresponding to the difference to correspond to each other; and

controlling the distribution ratio of the distributor based on the acquired control value.