Effect of Silicon Surface Cleaning on the Initial Stage of Selective Titanium Silicide Chemical Vapor Deposition

The influence of silicon surface cleanness on the nuclei density of titanium silicide in the initial stage of selective chemical vapor deposition was studied. The nuclei density was greatly increased as the cleanness of the silicon surface was improved. An in situ silicon surface cleaning using a low-pressure silane gas at a low temperature (700–740°C) was effective in increasing the nuclei density of titanium silicide. About a 500-A-thick titanium silicide film with a low resistivity near the bulk value and a smooth morphology has been obtained with full selectivity by in situ cleaning using silane gas.