Effects on Selective CVD of Titanium Disilicide by Substrate Doping and Selective Silicon Deposition

During selective chemical vapor deposition (CVD) of titanium disilicide on silicon, consumption of As implanted silicon substrates is enhanced relative to Si substrates implanted with other species. In this study, a selective epitaxially grown Si (SEG Si) layer has been deposited prior to selective CVD of titanium disilicide on samples with different implanted doses of either As or B. If no SEG Si film is deposited, the selective CVD TiSi2 film properties strongly depended on dopant type (As vs. B) and on dopant dose. Addition of a SEG Si film prior to selective CVD TiSi2 improves process stability as a function of changes in initial ion implanted conditions. Use of a SEG Si film prior to selective CVD TiSi2 results in values of TiSi2 thickness and TiSi2 sheet resistance which are approximately constant as a function of initial ion implant dose, and are approximately equal for both the As and B implanted samples used in this study.