In semiconductor manufacturing, low-k film deposition is common, but the chamber must be cleaned frequently to remove condensed matter during deposition.

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Traditionally, the chamber cleaning cycle has been a fixed-time process step with a sufficient margin of statistical variation to effectively estimate the worst-case scenario. However, if the endpoint of the cleaning process can be detected, this time can be reduced, dramatically increasing overall throughput.

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Existing measurement solutions using residual gas analyzers (RGA) and optical emission spectrometers (OES) are not effective. Nitrogen trifluoride (NF3) used for chamber cleaning is very corrosive (not practical) to the electron impact ionization source of the RGA, and OES requires a plasma that is not present during cleaning.

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Atonarp's Aston is a new approach with precise endpoint detection that reduces processing time without compromising process margins; Aston has been successfully deployed in low-κ dielectric film applications.

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In a recent on-tool, in-fab production study, Aston reduced the overall chamber clean cycle by up to 80%. This reduced the total cycle time for wafer deposition and chamber cleaning by more than 40% on a 5 wafer cycle.

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Aston's ability to generate pinpoint real-time data overcomes the problems of existing metrology solutions and enables accurate endpoint detection, resulting in a significant reduction in processing time.

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More information on Aston and an application brief on reducing cycle time for chamber cleaning in semiconductor manufacturing can be downloaded below.