Electrical and microstructures properties of polygate electrode in 0.5 μm CMOS devices

Abstract

The effect of phosphorus, doped by in-situ and by ion implantation on poly silicon, as a gate electrode of 0.5 μm CMOS was investigated. The result shows that a two-step annealing is required to cure the radiation damage and activate the dopant in reducing the sheet resistance of the ion implanted gate electrode. The introduction of phosphorus from 7×10 15 to 3×l0 l6/cm 3 by ion implantation at 40 keV has reduced the sheet resistance from 100 ohm/ to 25 ohm/ comparable to the gate produced by in-situ phosphorus doping. The microstructures of polysilicon gate electrode were studied using TEM. and found that grains of samples in polysilicon doped by in-situ are larger than other samples. © 2000 IEEE.