A simple method for extracting average doping concentration in the polysilicon and silicon surface layer near the oxide in polysilicon-gate MOS structures

摘要

The author demonstrates a simple technique that extracts average doping concentration in the polysilicon and silicon near the oxide in a metal/polysilicon/oxide/silicon system. The technique is based on the maximum-minimum capacitance method on two large area structures/spl minus/one MOSFET and one MOSC (MOS capacitor). The technique is simple and reliable since only three data points in the C-V data are required/spl minus/two points in MOSC C-V and one point in MOSFET C-V. The technique avoids inaccuracy caused by interface traps at the polysilicon/oxide and the oxide/silicon interface. The technique can be implemented into fab routine electric-test procedures for simultaneously monitoring change of doping concentration in polysilicon and silicon during process development.