# US 10,872,747 B2 · Controlling showerhead heating via resistive thermal measurements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,872,747 B2 - Document ID: US10872747B2 - Status: Granted - Kind: B2 - Application number: 16/058,090 - Filed: 2018-08-08 - Published: 2020-02-13 - Granted: 2020-12-22 - Earliest claimed: 2018-08-08 - Assignees: Lam Research Corporation - Applicants: Lam Research Corporation - Inventors: Nick Ray Linebarger, Jr.; Curtis W. Bailey; Easwar Srinivasan; Devon Pelkey - Web page: https://patentgrep.com/patent/US10872747B2 ## CPC - H01J 37/32449: {Gas control, e.g. control of the gas flow} - G01K 1/14: Supports; Fastening devices; Arrangements for mounting thermometers in particular locations - G01K 7/16: using resistive elements - G01K 15/005: {Calibration} - H05B 1/0233: {for semiconductors manufacturing} - H05B 3/22: non-flexible - H10P 72/0432: {mainly by conduction} - H10P 72/0602: {Temperature monitoring} - H01J 37/32724: {Temperature} - H01J 2237/002: Cooling arrangements - H01J 2237/24585: Other variables, e.g. energy, mass, velocity, time, temperature - H10P 72/0402: {Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence)} - H10P 72/722: {Details of electrostatic chucks} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A showerhead for a plasma chamber comprises a resistive heater configured to receive power to heat the showerhead of the plasma chamber, and a resistive element thermally bonded to the showerhead of the plasma chamber. The resistive element changes resistance in response to a change in temperature of the showerhead. The resistive element is encapsulated in an insulating material to electrically insulate the resistive element from the showerhead. The insulating material is a good conductor of heat. The power to the resistive heater is received based on the resistance of the resistive element. ## Claims ### Claim 1 A system for measuring a temperature of a showerhead of a plasma chamber and controlling heating of the showerhead based on the temperature, the system comprising: a resistive heater to heat the showerhead of the plasma chamber; a resistive element thermally bonded to the showerhead of the plasma chamber, wherein the resistive element includes a single metal that changes resistance in response to a change in temperature of the single metal; and a controller configured to: supply power to the resistive heater to heat the showerhead; supply voltage to the resistive element; measure current through the resistive element; determine resistance of the resistive element based on the voltage supplied to the resistive element and the current measured through the resistive element; determine the temperature of the showerhead based on the resistance of the resistive element; compare the temperature to a setpoint temperature for the showerhead; and control the supply of power to the resistive heater based on the comparison to control the heating of the showerhead, wherein the power supplied to the resistive heater includes AC power and wherein the voltage supplied to the resistive element includes DC voltage. ### Claim 2 (depends on 1) The system of claim 1 wherein the controller is configured to determine the temperature of the showerhead using a lookup table generated by performing an in situ calibration of the resistive element. ### Claim 3 (depends on 1) The system of claim 1 wherein the controller is configured to: increase the power supplied to the resistive heater in response to the temperature of the showerhead being less than or equal to the setpoint temperature; and decrease the power supplied to the resistive heater in response to the temperature of the showerhead being greater than or equal to the setpoint temperature. ### Claim 4 (depends on 1) The system of claim 1 wherein the resistive element is encapsulated in an insulating material to electrically insulate the resistive element from the showerhead and wherein the insulating material is a good conductor of heat. ### Claim 5 (depends on 1) The system of claim 1 wherein the determination of the resistance of the resistive element is immune to a DC bias associated with the showerhead. ### Claim 6 (depends on 5) The system of claim 5 wherein the DC bias is induced by plasma in the plasma chamber. ### Claim 7 (depends on 5) The system of claim 5 wherein the DC bias is applied to the showerhead to control flow of particles in the plasma chamber. ### Claim 8 (depends on 1) The system of claim 1 wherein the showerhead comprises a first electrode, the system further comprising: a substrate support configured to support a substrate during processing, the substrate support comprising a second electrode; an RF generator configured to generate RF power; and a gas delivery system configured to supply process gas in the plasma chamber, wherein the controller is further configured to apply the RF power across the first electrode and the second electrode in response to the process gas being supplied to strike plasma in the plasma chamber, and wherein the determination of the resistance of the resistive element is unaffected by a DC bias induced by the plasma on the showerhead. ### Claim 9 (depends on 8) The system of claim 8 wherein: the controller is configured to apply a DC bias to the showerhead to control flow of particles in the plasma chamber; and the determination of the resistance of the resistive element is unaffected by the DC bias applied to the showerhead. ### Claim 10 (depends on 1) The system of claim 1 further comprising: a second resistive element thermally bonded to the showerhead, wherein the second resistive element includes the single metal; and wherein the controller is configured to: supply the voltage to the second resistive element; measure current through the second resistive element; determine resistance of the second resistive element based on the voltage supplied to the second resistive element and the current measured through the second resistive element; determine a second temperature of the showerhead based on the resistance of the second resistive element; compare the second temperature to a predetermined temperature threshold; and stop the supply of power to the resistive heater in response to the second temperature being greater than or equal to the predetermined temperature threshold to prevent the showerhead from overheating. ### Claim 11 (depends on 1) The system of claim 1 further comprising: a second resistive element thermally bonded to the showerhead, wherein the second resistive element includes the single metal; and wherein the controller is configured to: supply the voltage to the second resistive element; measure current through the second resistive element; determine resistance of the second resistive element based on the voltage supplied to the second resistive element and the current measured through the second resistive element; determine a second temperature of the showerhead based on the resistance of the second resistive element; determine an average temperature of the showerhead based on the temperature and the second temperature; compare the average temperature to the setpoint temperature; and control the supply of power to the resistive heater based on the comparison. ### Claim 12 (depends on 1) The system of claim 1 further comprising: a second resistive heater arranged in a different location than a location of the resistive heater in the showerhead to heat the showerhead; a second resistive element thermally bonded to the showerhead proximate to the different location, wherein the second resistive element includes the single metal; and wherein the controller is configured to: supply the voltage to the second resistive element; measure current through the second resistive element; determine resistance of the second resistive element based on the voltage supplied to the second resistive element and the current measured through the second resistive element; determine a second temperature of the showerhead based on the resistance of the second resistive element; compare the second temperature to the setpoint temperature; and control the supply of power to the second resistive heater based on the comparison. ### Claim 13 (depends on 12) The system of claim 12 wherein the controller is configured to determine the temperature of the showerhead using a second lookup table generated by performing an in situ calibration of the second resistive element. ### Claim 14 A system comprising: a resistive heater configured to receive power to heat a showerhead of a plasma chamber; a resistive element thermally bonded to the showerhead of the plasma chamber, wherein the resistive element changes resistance in response to a change in temperature of the showerhead, wherein the resistive element is encapsulated in an insulating material to electrically insulate the resistive element from the showerhead, wherein the insulating material is a good conductor of heat, and wherein the power to the resistive heater is received based on the resistance of the resistive element; and a controller configured to: supply the power to the resistive heater; supply a voltage to the resistive element; measure a current through the resistive element; determine the resistance of the resistive element based on the voltage supplied to the resistive element and the current measured through the resistive element; determine the temperature of the showerhead based on the resistance of the resistive element; compare the temperature to a setpoint temperature for the showerhead; and control the supply of the power to the resistive heater based on the comparison to control the heating of the showerhead, wherein the determination of the resistance of the resistive element is immune to a DC bias associated with the showerhead. ### Claim 15 (depends on 14) The system of claim 14 wherein the controller is configured to determine the temperature of the showerhead using a lookup table generated by performing an in situ calibration of the resistive element. ### Claim 16 (depends on 14) The system of claim 14 wherein the controller is configured to: increase the power supplied to the resistive heater in response to the temperature of the showerhead being less than or equal to the setpoint temperature; and decrease the power supplied to the resistive heater in response to the temperature of the showerhead being greater than or equal to the setpoint temperature. ### Claim 17 (depends on 14) The system of claim 14 wherein the DC bias is induced by plasma in the plasma chamber. ### Claim 18 (depends on 14) The system of claim 14 wherein the DC bias is applied to the showerhead to control flow of particles in the plasma chamber. ### Claim 19 (depends on 14) The system of claim 14 wherein the showerhead comprises a first electrode, the system further comprising: a substrate support configured to support a substrate during processing, the substrate support comprising a second electrode; an RF generator configured to generate RF power; and a gas delivery system configured to supply process gas in the plasma chamber, wherein the controller is further configured to apply the RF power across the first electrode and the second electrode in response to the process gas being supplied to strike plasma in the plasma chamber, and wherein the determination of the resistance of the resistive element is unaffected by a DC bias induced by the plasma on the showerhead. ### Claim 20 (depends on 19) The system of claim 19 wherein: the controller is configured to apply a DC bias to the showerhead to control flow of particles in the plasma chamber; and the determination of the resistance of the resistive element is unaffected by the DC bias applied to the showerhead. ### Claim 21 (depends on 14) The system of claim 14 wherein the power supplied to the resistive heater includes AC power and wherein the voltage supplied to the resistive element includes DC voltage. ### Claim 22 (depends on 14) The system of claim 14 further comprising: a second resistive element thermally bonded to the showerhead; and wherein the controller is configured to: supply the voltage to the second resistive element; measure current through the second resistive element; determine resistance of the second resistive element based on the voltage supplied to the second resistive element and the current measured through the second resistive element; determine a second temperature of the showerhead based on the resistance of the second resistive element; compare the second temperature to a predetermined temperature threshold; and stop the supply of power to the resistive heater in response to the second temperature being greater than or equal to the predetermined temperature threshold to prevent the showerhead from overheating. ### Claim 23 (depends on 22) The system of claim 22 wherein the controller is configured to determine the temperature of the showerhead using a second lookup table generated by performing an in situ calibration of the second resistive element. ### Claim 24 (depends on 14) The system of claim 14 further comprising: a second resistive element thermally bonded to the showerhead; and wherein the controller is configured to: supply the voltage to the second resistive element; measure current through the second resistive element; determine resistance of the second resistive element based on the voltage supplied to the second resistive element and the current measured through the second resistive element; determine a second temperature of the showerhead based on the resistance of the second resistive element; determine an average temperature of the showerhead based on the temperature and the second temperature; compare the average temperature to the setpoint temperature; and control the supply of power to the resistive heater based on the comparison. ### Claim 25 (depends on 14) The system of claim 14 further comprising: a second resistive heater arranged in a different location than a location of the resistive heater in the showerhead to heat the showerhead; a second resistive element thermally bonded to the showerhead proximate to the different location; and wherein the controller is configured to: supply the voltage to the second resistive element; measure current through the second resistive element; determine resistance of the second resistive element based on the voltage supplied to the second resistive element and the current measured through the second resistive element; determine a second temperature of the showerhead based on the resistance of the second resistive element; compare the second temperature to the setpoint temperature; and control the supply of power to the second resistive heater based on the comparison.