Method to increase silicon nitride tensile stress using nitrogen plasma in-situ treatment and ex-situ uv cure

Abstract

Stress of a silicon nitride layer may be enhanced by deposition at higher temperatures. Employing an apparatus that allows heating of a substrate to substantially greater than 400° C. (for example a heater made from ceramic rather than aluminum), the silicon nitride film as-deposited may exhibit enhanced stress allowing for improved performance of the underlying MOS transistor device. In accordance with some embodiments, a deposited silicon nitride film is exposed to curing with plasma and ultraviolet (UV) radiation, thereby helping remove hydrogen from the film and increasing film stress. In accordance with other embodiments, a silicon nitride film is formed utilizing an integrated process employing a number of deposition/curing cycles to preserve integrity of the film at the sharp corner of the underlying raised feature. Adhesion between successive layers may be promoted by inclusion of a post-UV cure plasma treatment in each cycle.

1 .- 16 . (canceled) 
     
     
         17 . A method of forming a dielectric film on a substrate, comprising:
 placing a substrate with at least one formed feature across a surface of the substrate into a chamber;   depositing a dielectric layer on the surface of the substrate;   treating the dielectric layer with plasma; and   treating the dielectric layer with a UV source.   
     
     
         18 . The method of  claim 17 , further comprising repeating depositing a dielectric layer and treating the dielectric layer with a plasma. 
     
     
         19 . The method of  claim 17 , wherein the dielectric layer comprises silicon oxide, silicon oxynitride, silicon nitride, or doped silicon nitride. 
     
     
         20 . The method of  claim 17 , wherein the depositing a dielectric layer and treating the dielectric layer with plasma are performed in the same chamber. 
     
     
         21 . The method of  claim 17 , wherein the treating of the dielectric layer with a UV source is performed in a second chamber comprising a UV source. 
     
     
         22 . The method of  claim 17 , wherein the plasma includes argon, nitrogen, Xenon, or Helium. 
     
     
         23 . The method of  claim 17  further comprising treating the dielectric layer with plasma. 
     
     
         24 . The method of  claim 23 , further comprising repeating depositing a dielectric layer, treating the dielectric layer with a plasma, treating the dielectric layer with a UV source, and treating the dielectric layer with a plasma. 
     
     
         25 . The method of  claim 23 , wherein the depositing a dielectric layer, treating the dielectric layer with plasma, treating the dielectric layer with a UV source, and treating the dielectric layer with a plasma are performed in an integrated deposition/UV system. 
     
     
         26 . The method of  claim 23 , wherein the plasma includes argon, nitrogen, helium, or Xenon.