# US 7,407,324 B2 · Method and apparatus for monitoring the thickness of a conductive coating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,407,324 B2 - Document ID: US7407324B2 - Status: Granted - Kind: B2 - Application number: 11/200,013 - Filed: 2005-08-10 - Published: 2007-02-15 - Granted: 2008-08-05 - Earliest claimed: 2005-08-10 - Assignees: Tokyo Electron Limited - Inventors: Jozef Brcka - Web page: https://patentgrep.com/patent/US7407324B2 ## CPC - G01B 7/105: {for measuring thickness of coating} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract A method and apparatus for determining thickness of a metallic layer being deposited on a collector. The method includes applying an electromagnetic field to a conductive layer on the collector. Then the temperature or the change in temperature of the collector is determined. The metal thickness is determined as a function of the temperature or change in temperature. The apparatus includes a collector, a thermocouple associated with the collector, and a source of an electromagnetic field. ## Claims ### Claim 1 A method of monitoring the thickness of a generally conductive layer deposited on a collector, comprising: applying an electromagnetic field to the conductive layer; determining a temperature or a temperature change in the collector as a result of the electromagnetic field; and determining the thickness of the generally conductive layer deposited on the collector as a function of the temperature or the change in temperature, wherein the thickness determining includes comparing the temperature or the temperature change in the collector with a temperature or a change in temperature calculated from a thermal model using an estimated thickness and adjusting the estimated thickness until the calculated temperature or change in temperature approaches the temperature or change in temperature. ### Claim 2 (depends on 1) The method according to claim 1, wherein the determining of the thickness of the generally conductive layer occurs concurrently with deposition of metal on a workpiece. ### Claim 3 (depends on 1) The method according to claim 1, wherein the generally conductive layer is sputter deposited on the collector. ### Claim 4 (depends on 3) The method according to claim 3, wherein the generally conductive layer is sputter deposited in a metallization chamber. ### Claim 5 (depends on 1) The method according to claim 1, further comprising: determining a temperature Tref of a member whose temperature is not affected by said electromagnetic field, wherein said thickness determining is based on a difference between the temperature Tref and the temperature in the collector Tx after application of said electromagnetic field. ### Claim 6 (depends on 5) The method according to claim 5, wherein a plurality of different temperatures Tx are measured at different times, and the thickness determining is based on a temperature difference between temperature Tref and at least one of the plurality of different temperatures Tx. ### Claim 7 (depends on 6) The method according to claim 6, wherein the plurality of different temperatures is determined on a generally continuous basis. ### Claim 8 (depends on 6) The method according to claim 6, wherein the thickness determining is determined on a generally continuous basis. ### Claim 9 (depends on 6) The method according to claim 6, wherein the thickness of the generally conductive layer is determined in-situ. ### Claim 10 A method of monitoring the thickness of a generally conductive layer deposited on a collector, comprising: applying an electromagnetic field to the conductive layer; determining a temperature or a temperature change in the collector as a result of the electromagnetic field; and determining the thickness of the generally conductive layer deposited on the collector as a function of the temperature or the change in temperature, wherein the application of the electromagnetic field induces ohmic losses on the surface of the collector proportional to the thickness of the conductive layer deposited on the collector. ### Claim 11 (depends on 10) The method according to claim 10, wherein the determining of the thickness of the generally conductive layer occurs concurrently with deposition of metal on a workpiece. ### Claim 12 (depends on 10) The method according to claim 10, wherein the generally conductive layer is sputter deposited on the collector. ### Claim 13 (depends on 12) The method according to claim 12, wherein the generally conductive layer is sputter deposited in a metallization chamber. ### Claim 14 (depends on 10) The method according to claim 10, further comprising: determining a temperature Tref of a member whose temperature is not affected by said electromagnetic field, wherein said thickness determining is based on a difference between the temperature Tref and the temperature in the collector Tx after application of said electromagnetic field. ### Claim 15 (depends on 14) The method according to claim 14, wherein a plurality of different temperatures Tx are measured at different times, and the thickness determining is based on a temperature difference between temperature Tref and at least one of the plurality of different temperatures Tx. ### Claim 16 (depends on 15) The method according to claim 15, wherein the plurality of different temperatures is determined on a generally continuous basis. ### Claim 17 (depends on 15) The method according to claim 15, wherein the thickness determining is determined on a generally continuous basis. ### Claim 18 (depends on 15) The method according to claim 15, wherein the thickness of the generally conductive layer is determined in-situ.