Patent ID: 6998341

Claim:
A process for forming a refractory metal silicide stack with a diffusion barrier material nitride cover layer, the process comprising: depositing a layer of a refractory metal on a silicon surface layer in the presence of nitrogen, silicon surface layer being on a semiconductor substrate; annealing the layer of the refractory metal in the presence of nitrogen to form a layer of a silicide of the refractory metal; depositing multiple layers of a diffusion barrier material on a test semiconductor substrate in an environment of varying nitrogen content; determining a diffusion barrier material deposition rate as a function of nitrogen content; depositing a layer of the diffusion barrier material over the layer of the silicide of the refractory metal in an environment having a gaseous nitrogen content operating concentration; and growing nitride grains of the diffusion barrier material in the layer of the diffusion barrier material in an environment having a nitrogen content to form a layer of a nitride of the diffusion barrier material.