Electrical contact

Abstract

An electrical contact includes a substrate, at least an insulation layer, a metal layer, a conductive layer, and a metal silicide layer. The substrate includes at least a silicon region. The insulation layer is disposed on the substrate and includes at least a contact hole exposing the silicon region. The metal layer is formed on the sidewalls and the bottom of the contact hole. The metal layer adjacent to the bottom surface is thinner than the metal layer on the sidewalls. The conductive layer covers the metal layer and fills up the contact hole. The metal silicide layer is adjacent to the bottom of the contact hole.

What is claimed is: 
     
         1 . An electrical contact, comprising:
 a substrate having at least a silicon region;   at least an insulation layer on the substrate, wherein the insulation layer comprises at least a contact hole exposing the silicon region and having sidewalls and a bottom surface;   a metal layer formed on the sidewalls of the contact hole;   a conductive layer covering the metal layer, wherein the conductive layer fills up the contact hole; and   a metal silicide layer adjacent to the bottom of the contact hole, wherein the metal layer is further on the bottom and the metal layer adjacent to the bottom surface is thinner than the metal layer on the sidewalls.   
     
     
         2 . The electrical contact according to  claim 1 , furthering comprising a barrier layer disposed between the metal layer and the conductive layer. 
     
     
         3 . The electrical contact according to  claim 2 , wherein the barrier layer comprises TiN, TaN, Ti/TiN or Ta/TaN. 
     
     
         4 . The electrical contact according to  claim 1 , wherein the metal silicide layer substantially contacts the barrier layer. 
     
     
         5 . The electrical contact according to  claim 1 , wherein the metal silicide layer is adjacent to the metal layer. 
     
     
         6 . The electrical contact according to  claim 1 , wherein the metal layer is thinner than 150 Angstroms. 
     
     
         7 . The electrical contact according to  claim 1 , wherein the metal layer comprises tungsten, aluminum, copper, titanium, tantalum, niobium, erbium, molybdenum, cobalt, nickel, platinum or alloys thereof. 
     
     
         8 . The electrical contact according to  claim 1 , wherein the contact hole is a slot contact hole. 
     
     
         9 . The electrical contact according to  claim 1 , wherein the metal silicide layer and the metal layer have same metal components. 
     
     
         10 . An electrical contact, comprising:
 a substrate having at least a silicon region;   at least an insulation layer on the substrate, wherein the insulation layer comprises at least a contact hole exposing the silicon region and having sidewalls and a bottom surface;   a metal layer formed only on the sidewalls of the contact hole;   a conductive layer covering the metal layer, wherein the conductive layer fills up the contact hole;   a barrier layer located between the metal layer and the conductive layer; and   a metal silicide layer adjacent to the bottom of the contact hole, wherein the metal silicide layer and the metal layer have same metal components.   
     
     
         11 . The electrical contact according to  claim 10 , wherein the barrier layer comprises TiN, TaN, Ti/TiN or Ta/TaN. 
     
     
         12 . The electrical contact according to  claim 10 , wherein the metal silicide layer substantially contacts the barrier layer. 
     
     
         13 . The electrical contact according to  claim 10 , wherein the metal silicide layer is adjacent to the metal layer. 
     
     
         14 . The electrical contact according to  claim 10 , wherein the metal layer is thinner than 150 Angstroms. 
     
     
         15 . The electrical contact according to  claim 10 , wherein the metal layer comprises tungsten, aluminum, copper, titanium, tantalum, niobium, erbium, molybdenum, cobalt, nickel, platinum or alloys thereof.