Patent ID: 7455448

Claim:
A method of determining the accuracy of calibration of an RTP chamber, comprising: (a) providing a test wafer including a sichrome layer on an insulating layer, wherein the insulating layer is formed on a silicon substrate, and wherein the sichrome layer having a pre-anneal sheet resistance Rsi; (b) placing the test wafer in the RTP chamber and subjecting the test wafer to a predetermined annealing at a predetermined anneal temperature as measured by a temperature sensor in the RTP chamber for a predetermined anneal duration; (c) measuring a sheet resistance of the sichrome layer to determine a post-anneal sheet resistance Rsf; (d) computing a sheet resistance change ΔRs of the sichrome layer by subtracting the post-anneal sheet resistance Rsf from the pre-anneal sheet resistance Rsi; (e) determining an actual value of an anneal temperature corresponding to the computed sheet resistance change ΔRs from predetermined characterizing information representative of ΔRs of the sichrome layer as a function of anneal temperature and anneal duration; and (f) determining the accuracy of calibration of the RTP chamber by determining the difference between the actual anneal temperature determined in step (e) and the predetermined anneal temperature as measured by the temperature sensor.