A low frequency AC method to measure the doping profile in the channel region of a MOSFET with general extendability to the semiconductor surface

A method is presented to measure the doping profile in the channel region of a MOSFET from the small signal AC parameter, dV/sub SB//dV/sub GS/, and to display the doping profile on the screen of a parameter analyzer. The depletion depth is directly proportional to dV/sub SB//dV/sub GS/, and the doping density is proportional to its first V/sub GS/ derivative. It is shown how the method can be extended to determine the doping profile near the semiconductor surface. This extension method is applicable to any MOSFET dopant profiling technique based on measurements near threshold.<
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