14 September 1994 New surface minority carrier lifetime measurement technique
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An instrument is described which is designed as a production monitor for silicon wafer damage and contamination in the surface interface. The technique functions by putting the wafer are under test into a controlled depth of inversion. Then, the lifetime is measured by determining how much the inversion condition depletion width is affected by short wavelength light. The advantages of this technique, as implemented, over related methods include: (1) Only the interface region is measured. (2) The instrument measures simultaneously: Doping concentration, Oxide Charge, Interface trap density as well as surface lifetime, Ts. (3) The measurement of Ts is not affected by the wavers oxide charge since the instrument induces a compensating surface charge to put the wafer surface into a known depth of inversion. This is in contrast to other methods which require chemical manipulation of the wafer surface for a measurement if the oxide happens to have a charge which puts the semiconductor in the state of accumulation. Data is reported showing correlation of this technique with microwave PCD measurements and with measured Fe contamination values.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
William Goldfarb, William Goldfarb, "New surface minority carrier lifetime measurement technique", Proc. SPIE 2337, Optical Characterization Techniques for High-Performance Microelectronic Device Manufacturing, (14 September 1994); doi: 10.1117/12.186638; https://doi.org/10.1117/12.186638

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