# US 12,180,579 B2 · Method for monitoring process conditions of, and method for controlling, a plasma PVD process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,180,579 B2 - Document ID: US12180579B2 - Status: Granted - Kind: B2 - Application number: 17/913,353 - Filed: 2021-03-29 - Published: 2023-05-18 - Granted: 2024-12-31 - Earliest claimed: 2020-04-06 - Assignees: Ionautics AB - Applicants: Ionautics AB - Inventors: Daniel Lundin; Ulf Helmersson - Web page: https://patentgrep.com/patent/US12180579B2 ## CPC - C23C 14/35: by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} - C23C 14/345: {using substrate bias} - C23C 14/52: Means for observation of the coating process - C23C 14/54: Controlling or regulating the coating process - C23C 14/543: {using measurement on the vapor source} - H01J 37/3467: {Pulsed operation, e.g. HIPIMS} - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A method (200) for monitoring process conditions in a plasma PVD process as well as a method (300) for controlling a plasma PVD process are disclosed. The methods are performed in an apparatus (1) configured therefore. In accordance with the methods, an oscillating voltage signal is applied to a target (3), arranged in the apparatus (1), by means of a radio frequency generator 15). The response from the applied oscillating voltage signal is recorded by means of a radio frequency sensor (16). Based on the recorded response, information regarding at least one plasma process condition is derived. A computer program and a computer-readable medium are also disclosed. ## Claims ### Claim 1 A method for monitoring process conditions in a plasma PVD process, the plasma PVD process performed in an apparatus comprising: a process chamber, a target arranged inside the process chamber, a power supply arrangement connected to the target and configured to generate plasma discharges, a radio frequency generator, and a radio frequency sensor; the method comprising the steps of: when a plasma has been generated by means of the power supply arrangement, applying an oscillating voltage signal to the target by means of the radio frequency generator; recording a response from the applied oscillating voltage signal by means of the radio frequency sensor; and based on the recorded response, deriving information regarding at least one plasma process condition at the target, wherein the step of recording a response from the applied oscillating voltage signal comprises recording a response current amplitude and a current phase shift, and wherein the oscillating voltage signal is applied with a frequency of from 100 kHz to 1 MHz. ### Claim 2 (depends on 1) The method according to claim 1, wherein a peak-to-peak amplitude of the applied oscillating voltage signal is from 10 V to 300 V. ### Claim 3 (depends on 1) The method according to claim 1, wherein the power supply arrangement is configured to operate in a pulsed mode, and wherein the step of deriving information regarding at least one plasma process condition is performed based on a response recorded in between two active plasma discharge pulses as applied by the power supply arrangement. ### Claim 4 (depends on 1) The method according to claim 1, wherein the plasma PVD process is high-power impulse magnetron sputtering (HiPIMS). ### Claim 5 (depends on 1) The method according to claim 1, the method further comprising: during operation of the plasma PVD process, applying a second oscillating voltage signal to a probe arranged at a substrate position in the apparatus, recording a response from the second applied oscillating voltage signal, and based on the recorded response from the second applied oscillating voltage, deriving information regarding at least one plasma process condition at the substrate position. ### Claim 6 (depends on 1) A method for controlling a plasma PVD process performed in an apparatus, the apparatus comprising: a process chamber, a target arranged inside the process chamber, a power supply arrangement connected to the target and configured to generate plasma discharges, a radio frequency generator, and a radio frequency sensor; the method for controlling a plasma PVD process comprising the steps of: performing the method for monitoring process conditions according to claim 1; and based on the derived information regarding at least one plasma process condition at the target, adjusting an input signal to the power supply arrangement and/or an input signal to a gas supply device configured to introduce process gas into the process chamber, thereby adjusting plasma process conditions in the apparatus. ### Claim 7 (depends on 6) The method according to claim 6, wherein the method for controlling the plasma PVD process is performed continuously during the plasma PVD process. ### Claim 8 (depends on 6) The method according to claim 6, wherein the plasma PVD process is high-power impulse magnetron sputtering (HiPIMS). ### Claim 9 (depends on 1) A computer program comprising instructions which, when executed by a control device, cause the control device to carry out the method according to claim 1. ### Claim 10 (depends on 1) A computer-readable medium comprising instructions which, when executed by a control device, cause the control device to carry out the method according to claim 1. ### Claim 11 A plasma PVD process apparatus, comprising: a process chamber configured to comprise a target; a power supply arrangement configured to be connected to the target and configured to provide plasma discharges; a radio frequency generator configured to apply an oscillating voltage to the target when a plasma has been generated by means of the power supply arrangement; a radio frequency sensor configured to record a response from the applied oscillating voltage signal to the target; and a control device configured to derive information regarding at least one plasma process condition at the target based on the response recorded by the radio frequency sensor, wherein the response recorded by the radio frequency sensor comprises a response current amplitude and a current phase shift, and wherein the oscillating voltage is applied with a frequency of from 100 kHz to 1 MHz. ### Claim 12 (depends on 11) The plasma PVD process apparatus according to claim 11, wherein the power supply arrangement is configured to be operated in a pulsed mode, and wherein the control device is configured to derive information regarding the at least one plasma process condition based on the response recorded by the radio frequency sensor between plasma discharge pulses applied by the power supply arrangement. ### Claim 13 (depends on 11) The plasma PVD process apparatus according to claim 11, wherein the control device is further configured to adjust an input signal to the power supply arrangement, and/or an input signal to a gas supply device configured to introduce process gas into the process chamber, based on the derived information regarding at least one plasma process condition at er close to the target for the purpose of adjusting plasma process conditions in-situ. ### Claim 14 (depends on 11) The plasma PVD process apparatus according to claim 11, wherein the apparatus is a high-power impulse magnetron sputtering (HiPIMS) apparatus. ### Claim 15 A method for monitoring process conditions in a plasma PVD process, the plasma PVD process performed in an apparatus comprising: a process chamber, a target arranged inside the process chamber, a power supply arrangement connected to the target and configured to generate plasma discharges, a radio frequency generator, and a radio frequency sensor; the method comprising the steps of: when a plasma has been generated by means of the power supply arrangement, applying an oscillating voltage signal to the target by means of the radio frequency generator; recording a response from the applied oscillating voltage signal by means of the radio frequency sensor; and based on the recorded response, deriving information regarding at least one plasma process condition in a vicinity of the target, wherein the step of recording a response from the applied oscillating voltage signal comprises recording a response current amplitude and a current phase shift, and wherein the oscillating voltage signal is applied with a frequency of from 100 kHz to 1 MHz. ### Claim 16 (depends on 15) A method for controlling a plasma PVD process performed in an apparatus, the apparatus comprising: a process chamber, a target arranged inside the process chamber, a power supply arrangement connected to the target and configured to generate plasma discharges, a radio frequency generator, and a radio frequency sensor; the method for controlling a plasma PVD process comprising the steps of: performing the method for monitoring process conditions according to claim 15; and based on the derived information regarding at least one plasma process condition in the vicinity of the target, adjusting an input signal to the power supply arrangement and/or an input signal to a gas supply device configured to introduce process gas into the process chamber, thereby adjusting plasma process conditions in the apparatus. ### Claim 17 (depends on 16) The method according to claim 16, wherein the plasma PVD process is high-power impulse magnetron sputtering (HiPIMS). ### Claim 18 (depends on 15) The method according to claim 15, wherein the at least one plasma process condition is an ion flux, a plasma sheath impedance, an electron temperature, or an electron density. ### Claim 19 (depends on 15) A computer program comprising instructions which, when executed by a control device, cause the control device to carry out the method according to claim 15. ### Claim 20 (depends on 1) The method according to claim 1, wherein the at least one plasma process condition is an ion flux, a plasma sheath impedance, an electron temperature, or an electron density.