AVS 56th International Symposium & Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS2-ThA

Paper PS2-ThA10
Wafer Temperature Response During Plasma Etching and Applications to Chamber Matching

Thursday, November 12, 2009, 5:00 pm, Room B2

Session: Plasma Diagnostics, Sensors, and Control II
Presenter: J. Shields, Spansion, Inc.
Authors: J. Shields, Spansion, Inc.
C. Gabriel, Spansion, Inc.
Correspondent: Click to Email
As dimensions shrink, wafer temperature plays an increasingly important role in plasma etch process control. Temperature, however, is usually only monitored indirectly by measuring the chuck temperature or the coolant temperature during processing. To address these issues, we have employed the wireless KLA SensArray Integral wafer to measure the actual wafer temperature at 65 locations during wafer processing in a dielectric etch chamber with three different RF frequencies available. The Integral wafer records the temperature up to several times per second on internal memory, which is then downloaded to a computer after processing is completed. We conducted tests with no RF power, to determine effect of upper electrode and lower electrode temperatures on the wafer. We then measured the temperature response under variable RF excitation conditions for three different process chemistries utilized for dielectric and organic etching. For each process chemistry, comparisions between different excitation frequencies and combinations of frequencies were performed. The dependence of wafer temperature average and uniformity on backside helium cooling was determined, including a series of tests with no backside helium to isolate the effect of just RF delivered power. Finally, the promising application of this technique to chamber matching activities was analyzed.