# US 10,309,014 B2 · Method of cleaning a plasma processing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,014 B2 - Document ID: US10309014B2 - Status: Granted - Kind: B2 - Application number: 15/590,063 - Filed: 2017-05-09 - Published: 2017-11-30 - Granted: 2019-06-04 - Earliest claimed: 2016-05-24 - Assignees: SPTS Technologies Limited - Applicants: Spts Technologies Limited - Inventors: Kathrine Crook; Mark Carruthers; Andrew Price - Web page: https://patentgrep.com/patent/US10309014B2 ## CPC - C23C 16/4405: {Cleaning of reactor or parts inside the reactor by using reactive gases} - B08B 7/0035: {by radiant energy, e.g. UV, laser, light beam or the like} - C23C 16/452: by activating reactive gas streams before {their} introduction into the reaction chamber, e.g. by {ionisation} or addition of reactive species - C23C 16/52: Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} - H01J 37/32357: {Generation remote from the workpiece, e.g. down-stream} - H01J 37/32862: {In situ cleaning of vessels and/or internal parts} - H01J 37/32963: {End-point detection} - H01J 2237/335: Cleaning - 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) - B08B: CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A method of cleaning a chamber of a plasma processing device with radicals includes creating a plasma within a remote plasma source which is separated from the chamber, the plasma including radicals and ions, cleaning the chamber by allowing radicals to enter the chamber from the remote plasma source while preventing the majority of the ions created in the remote plasma source from entering the chamber, detecting a DC bias developed on a component of the chamber during cleaning; and using the detected DC bias to determine an end-point of the cleaning and, on determination of the end-point, to stop the cleaning. ## Claims ### Claim 1 A method of cleaning a chamber of a plasma processing device, comprising the steps of: creating a plasma within a remote plasma source which is separated from the chamber, the plasma comprising radicals and ions; cleaning the chamber with the radicals created in the remote plasma source by allowing the radicals to enter the chamber from the remote plasma source while preventing a majority of the ions created in the remote plasma source from entering the chamber and without producing charged particles anywhere in the chamber; detecting a DC bias developed on a component of the chamber during the cleaning; and using the detected DC bias to determine an end-point of the cleaning and, on determination of the end-point, to stop the cleaning. ### Claim 2 (depends on 1) A method according to claim 1 in which the component is a component of a gas inlet system. ### Claim 3 (depends on 2) A method according to claim 2 in which the component acts as a conduit for radicals produced in the remote plasma source. ### Claim 4 (depends on 3) A method according to claim 3 in which the component is a showerhead. ### Claim 5 (depends on 1) A method according to claim 1 in which the component is a substrate support disposed in the chamber, an electrically isolated portion of a wall of the chamber, or a pumping gallery. ### Claim 6 (depends on 1) A method according to claim 1 in which the plasma processing device is a PECVD device. ### Claim 7 (depends on 1) A method according to claim 1 in which the end-point is determined by detecting that the DC bias has attained a steady-state. ### Claim 8 (depends on 1) A method according to claim 1 in which the cleaning is performed using F radicals. ### Claim 9 (depends on 8) A method according to claim 8 in which the plasma created within the remote plasma source uses NF3 as a precursor. ### Claim 10 (depends on 1) A method according to claim 1 in which the chamber is cleaned after one or more dielectric films have been deposited in the chamber. ### Claim 11 (depends on 10) A method according to claim 10 in which each said at least one or more of the dielectric films is a film of a silicon containing dielectric material. ### Claim 12 (depends on 11) A method according to claim 11 in which the silicon containing dielectric material is silicon dioxide or silicon nitride. ### Claim 13 (depends on 1) A method according to claim 1 in which the cleaning of the chamber and the detecting of the DC bias are carried out while the remote plasma source is electrically floating with respect to the chamber. ### Claim 14 A method of cleaning a plasma processing device, comprising the steps of: creating a plasma within a remote plasma source which is separated from a process section of the device including a process chamber having a main body delimiting a process space in which plasma processing is carried out by the device and a conduit leading from the process space to a pump for exhausting gas from the process space, the plasma comprising radicals and ions; cleaning the process chamber with the radicals created in the remote plasma source by allowing the radicals to enter the process chamber from the remote plasma source while preventing a majority of the ions created in the remote plasma source from entering the process chamber and without producing charged particles anywhere in the process chamber; detecting a DC bias developed on a component of the process section during the cleaning; and using the detected DC bias to determine an end-point of the cleaning and, on determination of the end-point, to stop the cleaning. ### Claim 15 (depends on 14) A method according to claim 14 in which the component is a component of a gas inlet system connected to the main body of the process chamber. ### Claim 16 (depends on 14) A method according to claim 14 in which the component is a substrate support disposed in the main body of the process chamber, an electrically isolated portion of a wall of the main body of the process chamber, or a pumping gallery constituting the conduit. ### Claim 17 A method of cleaning a process chamber of a plasma processing device, comprising the steps of: creating a plasma within a remote plasma source which is separated from the process chamber, the plasma comprising radicals and ions; cleaning the process chamber with the radicals created in the remote plasma source by allowing the radicals to enter the process chamber from the remote plasma source while preventing a majority of the ions created in the remote plasma source from entering the process chamber; detecting a DC bias developed on a component of the plasma processing device during the cleaning; and using the detected DC bias to determine an end-point of the cleaning and, on determination of the end-point, to stop the cleaning, wherein the plasma is created by introducing source gas into the remote plasma source and exciting the source gas, and the cleaning of the process chamber and the detecting of the DC bias are carried out without exciting gas to produce a plasma anywhere else in the plasma processing device but in the remote plasma source. ### Claim 18 (depends on 17) A method according to claim 17 in which the component is a component of a gas inlet system. ### Claim 19 (depends on 18) A method according to claim 18 in which the component acts as a conduit for radicals produced in the remote plasma source. ### Claim 20 (depends on 19) A method according to claim 19 in which the component is a showerhead. ### Claim 21 (depends on 17) A method according to claim 17 in which the component is a substrate support, an electrically isolated portion of a wall of the process chamber, or a pumping gallery.