# US 10,770,267 B1 · Methods and apparatus for supplying RF power to plasma chambers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,267 B1 - Document ID: US10770267B1 - Status: Granted - Kind: B1 - Application number: 16/526,143 - Filed: 2019-07-30 - Granted: 2020-09-08 - Earliest claimed: 2019-07-30 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Smbat Kartashyan; David Totedo; Kartik Ramaswamy; Jay Merkel; Omid Amirkiai - Web page: https://patentgrep.com/patent/US10770267B1 ## CPC - H01J 37/32183: {Matching circuits} - H03H 7/0115: {comprising only inductors and capacitors (H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence)} - H03H 7/38: Impedance-matching networks - H03H 7/40: Automatic matching of load impedance to source impedance - H01J 2237/334: Etching - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract Methods and apparatus for matching an impedance of a process chamber with an impedance of an RF power source. In some embodiments, a method comprises dynamically matching a load impedance of the process chamber with an impedance matching circuit coupled between an RF power source and the process chamber, the impedance matching circuit configured to compensate for changes in the load impedance to match an impedance of the RF power source over a wide range of load impedances; filtering power feeding back from the process chamber with a first filter positioned between the matching circuit and the process chamber, the first filter configured as a wide bandpass filter; and filtering residual signals with a second filter positioned between the matching circuit and the RF power source, the second filter configured as a low pass filter. ## Claims ### Claim 1 A method for matching an impedance of a process chamber, comprising: dynamically matching a load impedance of the process chamber with an impedance matching circuit coupled between a radio frequency (RF) power source and the process chamber, the impedance matching circuit configured to compensate for changes in the load impedance to match an impedance of the RF power source over a wide range of load impedances; filtering power feeding back from the process chamber with a first filter positioned between the impedance matching circuit and the process chamber, the first filter configured as a wide bandpass filter; and filtering residual signals with a second filter positioned between the impedance matching circuit and the RF power source, the second filter configured as a low pass filter. ### Claim 2 (depends on 1) The method of claim 1, wherein the first filter is a second order filter. ### Claim 3 (depends on 1) The method of claim 1, wherein the second filter is at least a first order filter. ### Claim 4 (depends on 1) The method of claim 1, wherein the second filter is at least a third order filter. ### Claim 5 (depends on 1) The method of claim 1, further comprising: configuring parameters of the first filter to have a time constant such that the first filter operates at a frequency at least two times higher than a working frequency of the RF power source. ### Claim 6 (depends on 1) The method of claim 1, further comprising: configuring the first filter and the second filter to provide a combined fifth order filter. ### Claim 7 (depends on 6) The method of claim 6, wherein the combined fifth order filter has an attenuation of approximately 60 dB per decade to approximately 100 dB per decade of filtered frequencies. ### Claim 8 (depends on 1) The method of claim 1, further comprising: configuring the first filter to provide filtration of frequencies above a cutoff frequency. ### Claim 9 An apparatus for matching an impedance of a process chamber, comprising: an impedance matching circuit configured to compensate for an impedance loading of the process chamber to allow the impedance loading to match an impedance of a radio frequency (RF) power source connected to the process chamber; a first filter coupled between the impedance matching circuit and the process chamber, the first filter configured as a wide bandpass filter and configured to protect the RF power source from reverse power from the process chamber; and a second filter coupled between the impedance matching circuit and the RF power source, the second filter configured as a low pass filter to reduce residual signals from reaching the RF power source. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the first filter is a second order filter. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the second filter is at least a first order filter. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein the second filter is at least a third order filter. ### Claim 13 (depends on 9) The apparatus of claim 9, wherein the first filter is configured to have a time constant such that the first filter operates at a frequency at least two times higher than a working frequency of the RF power source. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the first filter and the second filter are configured to provide a combined fifth order filter with an attenuation of approximately 60 dB per decade to approximately 100 dB per decade of filtered frequencies. ### Claim 15 (depends on 9) The apparatus of claim 9, wherein the first filter is configured to provide filtration of frequencies above a cutoff frequency. ### Claim 16 An apparatus for providing power to a process chamber, comprising: a radio frequency (RF) power source configured to generate RF source energy to form a plasma in the process chamber; and an impedance matching network configured with: an impedance matching circuit configured to compensate for an impedance loading of the process chamber to allow the impedance loading to match an impedance of the RF power source connected to the process chamber; a first filter coupled between the impedance matching circuit and the process chamber, the first filter configured as a wide bandpass filter and configured to protect the RF power source from reverse power from the process chamber; and a second filter coupled between the impedance matching circuit and the RF power source, the second filter configured as a low pass filter to reduce residual signals from reaching the RF power source. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the first filter is a second order filter. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein the second filter is at least a first order filter. ### Claim 19 (depends on 16) The apparatus of claim 16, wherein the second filter is at least a third order filter. ### Claim 20 (depends on 16) The apparatus of claim 16, wherein the first filter is configured to have a time constant such that the first filter operates at a frequency at least two times higher than a working frequency of the RF power source.