Sticking coefficient of boron and phosphorus on silicon during vapor-phasedoping

A surface reaction model for boron and phosphorus atoms on silicon during v apor-phase doping is proposed by calculating their sticking coefficients. I n boron doping, two sticking configurations are found: a low B2H6-concentra tion case, and a high B2H6-concentration case. In the low B2H6-concentratio n case, a low sticking coefficient is maintained during doping, and in whic h hydrogen desorption from the surface opens more sites for boron chemisorp tion. In the high B2H6-concentration case, excessively chemisorbed boron at oms react with each other, causing boron segregation. A low sticking coeffi cient is preferred in order to avoid boron segregation and to control the c oncentration. In the phosphorus doping, the sticking coefficient was much l ower than that of boron, and phosphorus does not segregate on silicon. (C) 2001 American Vacuum Society.