A SIMPLE METHOD FOR EXTRACTING AVERAGE DOPING CONCENTRATION IN THE POLYSILICON AND SILICON SURFACE-LAYER NEAR THE OXIDE IN POLYSILICON-GATE MOS STRUCTURES

This letter 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 [1] on two large area structures-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-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 can be implemented into Fab routine electric-test (E-test) procedures for simultaneously monitoring change of doping concentration in polysilicon and silicon during process development.