US 2004/0171241 A1 · Semiconductor device having gate electrode of polymetal gate structure processed by side nitriding in anmonia atmosphere

Abstract

A semiconductor device has a reduced contact resistance between a tungsten film and a polysilicon layer and has a gate electrode prevented from being depleted for a reduced gate resistance. According to a method of fabricating such a semiconductor device, a semiconductor device having a gate electrode of a polymetal gate structure which comprises a three-layer structure having a tungsten (W) film, a tungsten nitride (WN) film, and a polysilicon (PolySi) layer, is manufactured by nitriding the sides of the gate electrode at a nitriding temperature ranging from 700° C. to 950° C. in an ammonia atmosphere after the gate electrode is formed and before side selective oxidization is performed on the gate electrode.

Claims10

Dependent claims

A method of fabricating a semiconductor device having a gate electrode of a polymetal gate structure which comprises a three-layer structure having a metal film, a barrier film, and a polysilicon layer, comprising the steps of:

successively forming a gate insulating film, a polysilicon layer, a barrier film, and a metal film on a semiconductor substrate;
etching said metal film, said barrier film, and said polysilicon layer to form a gate electrode;
effecting side nitridation on said gate electrode at a nitriding temperature ranging from 700° C. to 950° C. in an ammonia atmosphere;
and
effecting side selective oxidization to oxidize said polysilicon layer and silicon in said semiconductor substrate without oxidizing said metal film.

2 more elements

Dependencies are inferred from the claim text.

Semiconductor device having gate electrode of polymetal gate structure processed by side nitriding in anmonia atmosphere

Life of this patent

Semiconductor device having gate electrode of polymetal gate structure processed by side nitriding in anmonia atmosphere

Life of this patent

Abstract

Claims10