FORMATION OF FULLY SILICIDED GATE WITH OXIDE BARRIER ON THE SOURCE/DRAIN SILICIDE REGIONS

摘要

A simple and cost effective method of forming a fully suicided (FUSI) gate (2) of a MOS transistor (1) is disclosed. In one example, the method comprises forming a nitride hardmask overlying a polysilicon gate, forming an S/D suicide (4) in source/drain (10, 11) regions of the transistor, oxidizing a portion of the S/D suicide to form an oxide barrier overlying the S/D suicide in the source/drain regions, removing the nitride hardmask from the polysilicon (12) gate, and forming a gate suicide such as by deposition of a gate suicide metal over the polysilicon gate and the oxide barrier in the source/drain regions to form a fully suicided (FUSI) gate in the transistor. Thus, the oxide barrier protects the source/drain regions from additional suicide formation by the gate suicide metal formed thereafter. The method may further comprise selectively removing the oxide barrier in the source/drain regions after forming the fully suicided (FUSI) gate.