Modeling and Simulation of Arsenic-Doped-Silicon Low-Pressure Chemical Vapor Deposition

In this paper, we present the modeling and simulation of As-doped-Si low-pressure chemical vapor deposition (LPCVD), in which a Si film growth step using SiH 4 and an AsH 3 adsorption step are alternately performed (sequential doping is carried out). We focus on the Si film growth in the second step of sequential doping, which involves Si film growth (first step) → AsH 3 adsorption → Si film growth (second step). The growth thickness and As concentration in the Si film are evaluated with respect to deposition time. As atoms adsorbed on the Si surface after the AsH 3 adsorption step are taken up by the Si layer grown in the second step, and some of these atoms precipitate on the Si film surface. The adsorption of SiH 4 is suppressed owing to the effect of the As atoms precipitated on the Si film surface, resulting in a decrease in the growth rate of the Si film. On the basis of this finding, we construct a surface reaction model by determining the sticking coefficient of SiH 4 from the growth plots in the second step. The Si film growth profiles on submicron holes are analyzed by topography simulation using the surface reaction model, and simulation results are compared with experimentally obtained results.