Semiconductor structure with selectively deposited tungsten film and method for making the same

Abstract

A semiconductor structure is provided. The semiconductor structure includes a substrate; a dielectric layer overlying the substrate; a conductor pattern on a main surface of the dielectric layer, the conductor pattern having a top surface and sidewalls; and a conformal metal layer selectively deposited on the top surface and sidewalls, but without deposited on the main surface of the dielectric layer substantially.

1 . A semiconductor structure, comprising:
 a substrate;   a dielectric layer overlying the substrate;   a conductor pattern on a main surface of the dielectric layer, the conductor pattern having a top surface and sidewalls; and   a tungsten metal layer encompassing the conductor pattern including the top surface and the sidewalls, while leaving the main surface of the dielectric layer substantially free of the tungsten metal layer.   
     
     
         2 . The semiconductor structure according to  claim 1  wherein the dielectric layer comprises silicon oxide, silicon nitride or silicon oxy-nitride. 
     
     
         3 . The semiconductor structure according to  claim 1  wherein the conductor pattern comprises titanium, titanium nitride, tantalum, tantalum nitride, aluminum, copper, gold, tungsten, silicide or any combination thereof. 
     
     
         4 . (canceled) 
     
     
         5 . The semiconductor structure according to  claim 1  wherein the conductor pattern is made of titanium nitride. 
     
     
         6 . The semiconductor structure according to  claim 5  wherein the metal layer is a tungsten layer. 
     
     
         7 . The semiconductor structure according to  claim 6  wherein the tungsten layer has a thickness of less than 15 nanometers. 
     
     
         8 . The semiconductor structure according to  claim 1  wherein the dielectric layer is a gate dielectric layer of a vertical-channel transistor. 
     
     
         9 . The semiconductor structure according to  claim 8  wherein the conductor pattern is part of a metal gate or a word line. 
     
     
         10 . The semiconductor structure according to  claim 9  wherein the conductor pattern has a thickness of less than 15 nanometers. 
     
     
         11 . The semiconductor structure according to  claim 9  wherein the conductor pattern has a thickness of about 6-8 nanometers.