# US 2019/0246485 A1 · Plasma processing apparatus and method for controlling plasma processing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0246485 A1 - Document ID: US20190246485A1 - Status: Published application - Kind: A1 - Application number: 16/343,322 - Filed: 2017-10-12 - Published: 2019-08-08 - Earliest claimed: 2016-10-19 - Assignees: Tokyo Electron Limited; Tohoku University - Applicants: Tokyo Electron Limited; Tohoku University - Inventors: Masaki HIRAYAMA - Web page: https://patentgrep.com/patent/US20190246485A1 ## CPC - H05H 1/46: using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) - H01J 37/32183: {Matching circuits} - H01J 37/32577: {Electrical connecting means} - H10P 14/60: of insulating materials - H10P 50/242: {of Group IV materials} - H05H 2242/20: Power circuits - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A plasma processing apparatus according to one embodiment includes a grounded processing container, a mounting table configured to support a workpiece inside the processing container, a plurality of electrodes arranged to face the mounting table and insulated from one another, a high frequency power supply configured to supply a high frequency power for generating plasma and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container, and an impedance variable circuit configured to control an impedance and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container. ## Claims ### Claim 1 A plasma processing apparatus, comprising: a grounded processing container; a mounting table configured to support a workpiece inside the processing container; a plurality of electrodes arranged to face the mounting table and insulated from one another; a high frequency power supply configured to supply a high frequency power for generating plasma, and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container; and an impedance variable circuit configured to control an impedance, and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container. ### Claim 2 (depends on 1) The plasma processing apparatus of claim 1, wherein the plurality of electrodes includes a first electrode and a second electrode, wherein the high frequency power supply is electrically connected between the second electrode and the processing container, and wherein the impedance variable circuit is connected between the first electrode and the processing container. ### Claim 3 (depends on 2) The plasma processing apparatus of claim 2, wherein the first electrode is a disk-shaped center electrode, and the second electrode is an annular electrode surrounding an outer periphery of the center electrode, and wherein the high frequency power supply is electrically connected to the annular electrode and the processing container via a matching device. ### Claim 4 (depends on 3) The plasma processing apparatus of claim 3, wherein the annular electrode and the center electrode are formed of metal members, and an insulator member is interposed between the annular electrode and the center electrode. ### Claim 5 (depends on 3) The plasma processing apparatus of claim 3, further comprising a first coaxial tube, wherein one end of an inner conductor of the first coaxial tube is connected to the impedance variable circuit, and the other end of the inner conductor is connected to the center electrode. ### Claim 6 (depends on 3) The plasma processing apparatus of claim 3, further comprising a second coaxial tube including an inner conductor having a first portion and a plurality of second portions branched from the first portion, wherein an end portion of the first portion is connected to the matching device, and end portions of the plurality of second portions are connected to the annular electrode at positions axially symmetrical with respect to an axis passing through a center of the center electrode. ### Claim 7 (depends on 3) The plasma processing apparatus of claim 3, wherein an outer periphery of the workpiece, an outer periphery of a surface of the center electrode facing the mounting table, an inner periphery of a surface of the annular electrode facing the mounting table, and an outer periphery of the surface of the annular electrode facing the mounting table are circular, and wherein the workpiece, the center electrode, and the annular electrode have a relationship of an outer diameter of the surface of the annular electrode facing the mounting table>an outer diameter of the workpiece>an inner diameter of the surface of the annular electrode facing the mounting table>an outer diameter of the surface of the center electrode facing the mounting table. ### Claim 8 (depends on 1) The plasma processing apparatus of claim 1, wherein the plurality of electrodes includes a first electrode, a second electrode, and a third electrode, wherein the high frequency power supply is electrically connected between the second electrode and the third electrode, and wherein the impedance variable circuit is electrically connected between the first electrode and the third electrode. ### Claim 9 (depends on 8) The plasma processing apparatus of claim 8, wherein the high frequency power supply is electrically connected between the second electrode and the third electrode via a matching device, and wherein the third electrode is grounded via the matching device and the high frequency power supply. ### Claim 10 (depends on 9) The plasma processing apparatus of claim 9, wherein a common mode choke is provided in at least a part of a high frequency transmission path connecting the high frequency power supply and the third electrode. ### Claim 11 (depends on 9) The plasma processing apparatus of claim 9, wherein the first electrode is a disk-shaped center electrode, wherein the second electrode is an annular electrode surrounding an outer periphery of the center electrode, and wherein the third electrode is an outer peripheral electrode surrounding an outer periphery of the annular electrode. ### Claim 12 (depends on 11) The plasma processing apparatus of claim 11, wherein the center electrode, the annular electrode, and the outer peripheral electrode are formed of metal members, and wherein an insulator member is interposed between the center electrode and the annular electrode and between the annular electrode and the outer peripheral electrode. ### Claim 13 (depends on 11) The plasma processing apparatus of claim 11, further comprising a first coaxial tube, wherein one end of an inner conductor of the first coaxial tube is connected to the impedance variable circuit, and the other end of the inner conductor is connected to the center electrode. ### Claim 14 (depends on 11) The plasma processing apparatus of claim 11, further comprising a second coaxial tube including an inner conductor having a first portion and a plurality of second portions branched from the first portion, wherein an end portion of the first portion is connected to the matching device, and end portions of the plurality of second portions are connected to the annular electrode at positions axially symmetrical with respect to an axis passing through a center of the center electrode. ### Claim 15 (depends on 1) The plasma processing apparatus of claim 1, wherein the plurality of electrodes includes a first electrode and a second electrode, wherein the high frequency power supply is electrically connected between the first electrode and the second electrode, and wherein the impedance variable circuit is connected between the second electrode and the processing container. ### Claim 16 (depends on 15) The plasma processing apparatus of claim 15, wherein the high frequency power supply is electrically connected to the first electrode and the second electrode via a matching device, and wherein the second electrode is grounded via the matching device and the high frequency power supply. ### Claim 17 (depends on 16) The plasma processing apparatus of claim 16, wherein the first electrode is a disk-shaped center electrode, and wherein the second electrode is an outer peripheral electrode surrounding an outer periphery of the center electrode. ### Claim 18 (depends on 17) The plasma processing apparatus of claim 17, wherein the center electrode and the outer peripheral electrode are formed of metal members, and wherein an insulator member is interposed between the center electrode and the outer peripheral electrode. ### Claim 19 (depends on 17) The plasma processing apparatus of claim 17, further comprising a first coaxial tube, wherein one end of an inner conductor of the first coaxial tube is connected to the matching device, and the other end of the inner conductor is connected to the center electrode. ### Claim 20 (depends on 19) The plasma processing apparatus of claim 19, wherein one end of the inner conductor of the first coaxial tube is electrically short-circuited from an end portion of an outer conductor of the first coaxial tube. ### Claim 21 (depends on 19) The plasma processing apparatus of claim 19, further comprising a second coaxial tube having one end electrically connected to the first coaxial tube and the other end electrically connected to the matching device. ### Claim 22 (depends on 17) The plasma processing apparatus of claim 17, wherein an outer periphery of the workpiece, an outer periphery of a surface of the center electrode facing the mounting table, an inner periphery of a surface of the outer peripheral electrode facing the mounting table, and an outer periphery of the surface of the outer peripheral electrode facing the mounting table are circular, and wherein the workpiece, the center electrode, and the outer peripheral electrode have a relationship of an outer diameter of the surface of the outer peripheral electrode facing the mounting table>an outer diameter of the workpiece>an inner diameter of the surface of the outer peripheral electrode facing the mounting table>an outer diameter of the surface of the center electrode facing the mounting table. ### Claim 23 (depends on 17) The plasma processing apparatus of claim 17, wherein the impedance variable circuit is connected to the outer peripheral electrode at a plurality of positions axially symmetrical with respect to an axis passing through a center of the center electrode. ### Claim 24 (depends on 6) The plasma processing apparatus of claim 6, wherein the end portions of the plurality of second portions are connected to the annular electrode at positions equidistant in a circumferential direction of the annular electrode. ### Claim 25 (depends on 3) The plasma processing apparatus of claim 3, wherein the annular electrode is divided into a plurality of regions at equal intervals in a circumferential direction of the annular electrode. ### Claim 26 A method for controlling a plasma processing apparatus including a grounded processing container, a mounting table configured to support a workpiece inside the processing container, a plurality of electrodes arranged to face the mounting table and insulated from one another, a high frequency power supply configured to supply a high frequency power for generating plasma and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container, an impedance variable circuit configured to control an impedance and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container, and a monitor configured to measure a high frequency amplitude or a direct current potential on a surface of one electrode among the plurality of electrodes, the one electrode being connected to the impedance variable circuit, and the surface facing the mounting table, the method comprising: acquiring the high frequency amplitude or the direct current potential measured by the monitor; and controlling the impedance of the impedance variable circuit so that the high frequency amplitude or the direct current potential is set to a target value.