Method of making dense, conformal, ultra-thin cap layers for nanoporous low-k ild by plasma assisted atomic layer deposition

Abstract

Barrier layers and methods for forming barrier layers on a porous layer are provided. The methods can include chemically adsorbing a plurality of first molecules on a surface of the porous layer in a chamber and forming a first layer of the first molecules on the surface of the porous layer. A plasma can then be used to react a plurality of second molecules with the first layer of first molecules to form a first layer of a barrier layer. The barrier layers can seal the pores of the porous material, function as a diffusion barrier, be conformal, and/or have a negligible impact on the overall ILD k value of the porous material.

1 . A semiconductor device comprising:
 an interlevel dielectric (ILD) layer comprising a plurality of pores; and   a conformal barrier layer disposed at a surface of the ILD layer and not within the internal pores of the ILD.   
     
     
         2 . The semiconductor device of  claim 1 , wherein the conformal barrier layer seals a portion of the plurality of pores disposed at the surface of the ILD. 
     
     
         3 . A method for adjusting a pore size on a porous material comprising:
 providing a porous material, wherein the porous material comprises a plurality of pores having a diameter equal to or great than a first diameter;   chemically adsorbing a plurality of first molecules on a surface of the porous material in a chamber;   forming a first layer of the first molecules on the surface of the porous material; and   using a plasma to react a plurality of second molecules with the first layer of first molecules to form a first pore size reducing layer on the porous material, wherein the first pore size reducing layer reduces the diameter of the plurality of pores to less than the first diameter.   
     
     
         4 . The method of  claim 3 , further comprising forming a second pore size reducing layer on the first pore size reducing layer to further reduce the diameter of the plurality of pores. 
     
     
         5 . The method of  claim 3 , wherein the first layer changes a chemistry in the pores.