Sticking coefficient of boron and phosphorus on silicon during vapor-phase doping

A surface reaction model for boron and phosphorus atoms on silicon during vapor-phase doping is proposed by calculating their sticking coefficients. In boron doping, two sticking configurations are found: a low B2H6-concentration case, and a high B2H6-concentration case. In the low B2H6- concentration case, a low sticking coefficient is maintained during doping, and in which hydrogen desorption from the surface opens more sites for boron chemisorption. In the high B2H6-concentration case, excessively chemisorbed boron atoms react with each other, causing boron segregation. A low sticking coefficient is preferred in order to avoid boron segregation and to control the concentration. In the phosphorus doping, the sticking coefficient was much lower than that of boron, and phosphorus does not segregate on silicon.