# US 2018/0025891 A1 · Systems and methods for achieving a pre-determined factor associated with an edge region within a plasma chamber by synchronizing main and edge rf generators > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0025891 A1 - Document ID: US20180025891A1 - Status: Published application - Kind: A1 - Application number: 15/636,519 - Filed: 2017-06-28 - Published: 2018-01-25 - Earliest claimed: 2016-07-25 - Assignees: Lam Research Corporation - Applicants: Lam Research Corporation - Inventors: Alexei Marakhtanov; Felix Kozakevich; Michael C. Kellogg; John Patrick Holland; Zhigang Chen; Kenneth Lucchesi; Lin Zhao - Web page: https://patentgrep.com/patent/US20180025891A1 ## CPC - H01J 37/3299: {Feedback systems} - H01J 37/32091: {the radio frequency energy being capacitively coupled to the plasma} - H01J 37/32155: {Frequency modulation} - H01J 37/32165: {Plural frequencies} - H01J 37/32183: {Matching circuits} - H01J 37/32385: {Treating the edge of the workpieces} - H01J 37/32568: {Relative arrangement or disposition of electrodes; moving means} - H01J 37/32642: {Focus rings} - H01J 37/32715: {Workpiece holder} - H01J 37/32935: {Monitoring and controlling tubes by information coming from the object and/or discharge} - H10P 50/242: {of Group IV materials} - H10P 72/0421: {for drying etching} - H10P 72/7611: {characterised by edge profile or support profile} - H01J 2237/327: Arrangements for generating the plasma - H01J 2237/334: Etching - 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 Systems and methods for achieving a pre-determined factor associated with the edge region within the plasma chamber is described. One of the methods includes providing an RF signal to a main electrode within the plasma chamber. The RF signal is generated based on a frequency of operation of a first RF generator. The method further includes providing another RF signal to an edge electrode within the plasma chamber. The other RF signal is generated based on the frequency of operation of the first RF generator. The method includes receiving a first measurement of a variable, receiving a second measurement of the variable, and modifying a phase of the other RF signal based on the first measurement and the second measurement. The method includes changing a magnitude of a variable associated with a second RF generator to achieve the pre-determined factor. ## Claims ### Claim 1 A method for achieving a pre-determined factor associated with an edge region within a plasma chamber, comprising: providing a radio frequency (RF) signal via a first impedance matching circuit to a main electrode within the plasma chamber, wherein the RF signal is generated based on a frequency of operation of a first RF generator; providing another RF signal via a second impedance matching circuit to an edge electrode within the plasma chamber, wherein the other RF signal is generated based on the frequency of operation of the first RF generator; receiving a first measurement of a variable associated with an output of the first impedance matching circuit; receiving a second measurement of the variable associated with an output of the second impedance matching circuit; modifying a phase of the other RF signal based on the first measurement and the second measurement; and changing a magnitude of a variable associated with a second RF generator to achieve the pre-determined factor. ### Claim 2 (depends on 1) The method of claim 1, wherein changing the magnitude is performed after the other RF signal is generated and after the phase of the other RF signal is modified. ### Claim 3 (depends on 1) The method of claim 1, wherein modifying the phase of the RF signal and the other RF signal comprises modifying the phase to achieve a phase of the first measurement that is within a pre-set range from a phase of the second measurement. ### Claim 4 (depends on 1) The method of claim 1, wherein the variable associated with the second RF generator is different from the variable associated with the outputs of the first and second impedance matching circuits. ### Claim 5 (depends on 1) The method of claim 1, wherein receiving the first measurement comprises receiving the first measurement from the output of the first impedance matching circuit, wherein receiving the second measurement comprises receiving the second measurement from the output of the second impedance matching circuit. ### Claim 6 (depends on 1) The method of claim 1, wherein the main electrode is configured to support a substrate to process the substrate at a center region within the plasma chamber and the edge electrode is configured to process the substrate at the edge region. ### Claim 7 (depends on 1) The method of claim 1, wherein the main electrode is a chuck, and the edge electrode is an edge ring or a coupling ring. ### Claim 8 (depends on 1) The method of claim 1, wherein the main electrode is an upper electrode, and the edge electrode is an upper electrode extension. ### Claim 9 (depends on 1) The method of claim 1, wherein the second RF generator is controlled to have a frequency of operation that is within a pre-determined range of the frequency of operation of the first RF generator. ### Claim 10 A system for achieving a pre-determined factor associated with an edge region, comprising: a plasma chamber having a main electrode and an edge electrode; a first impedance matching circuit coupled to the main electrode; a second impedance matching circuit coupled to the edge electrode; a first radio frequency (RF) generator coupled to the first impedance matching circuit to provide an RF signal via the first impedance matching circuit to the main electrode, wherein the RF signal is generated based on a frequency of operation of the first RF generator; a second RF generator coupled to the second impedance matching circuit to provide another RF signal via the second impedance matching circuit to the edge electrode, wherein the other RF signal is generated based on the frequency of operation of the first RF generator, wherein the second RF generator is configured to receive a first measurement of a variable associated with an output of the first impedance matching circuit, wherein the second RF generator is configured to receive a second measurement of the variable associated with an output of the second impedance matching circuit, wherein the second RF generator is configured to modify a phase of the other RF signal based on the first measurement and the second measurement, and wherein the second RF generator is configured to change a magnitude of a variable associated with the second RF generator to achieve the pre-determined factor. ### Claim 11 (depends on 10) The system of claim 10, wherein the magnitude is changed after the other RF signal is generated and after the phase of the other RF signal is modified. ### Claim 12 (depends on 10) The system of claim 10, wherein the first measurement is received from the output of the first impedance matching circuit, wherein the second measurement is received from the output of the second impedance matching circuit. ### Claim 13 (depends on 10) The system of claim 10, wherein the second RF generator is configured to modify the phase of the other RF signal to achieve a phase of the first measurement that is within a pre-set range from a phase of the second measurement. ### Claim 14 (depends on 10) The system of claim 10, wherein the variable associated with the second RF generator is different from the variable associated with the outputs of the first and second impedance matching circuits. ### Claim 15 (depends on 10) The system of claim 10, wherein the second RF generator is controlled to have a frequency of operation that is within a pre-determined range of the frequency of operation of the first RF generator. ### Claim 16 (depends on 10) The system of claim 10, wherein the main electrode is configured to support a substrate to process the substrate at a center region within the plasma chamber and the edge electrode is configured to process the substrate at the edge region. ### Claim 17 (depends on 10) The system of claim 10, wherein the main electrode is a chuck, and the edge electrode is an edge ring or a coupling ring. ### Claim 18 (depends on 10) The system of claim 10, wherein the main electrode is an upper electrode, and the edge electrode is an upper electrode extension. ### Claim 19 A non-transitory computer readable medium containing program instructions for achieving a pre-determined factor associated with an edge region within a plasma chamber, wherein execution of the program instructions by one or more processors of a computer system causes the one or more processors to carry out operations of: providing a radio frequency (RF) signal via a first impedance matching circuit to a main electrode within the plasma chamber, wherein the RF signal is generated based on a frequency of operation of a first RF generator; providing another RF signal via a second impedance matching circuit to an edge electrode within the plasma chamber, wherein the other RF signal is generated based on the frequency of operation of the first RF generator; receiving a first measurement of a variable associated with an output of the first impedance matching circuit; receiving a second measurement of the variable associated with an output of the second impedance matching circuit; modifying a phase of the other RF signal based on the first measurement and the second measurement; and changing a magnitude of a variable associated with a second RF generator to achieve the pre-determined factor. ### Claim 20 (depends on 19) The non-transitory computer readable medium of claim 19, wherein changing the magnitude is performed after the other RF signal is generated and after the phase of the other RF signal is modified.