SIH_4 REACTION MECHANISM RESEARCH USING A FAST WAFER-ROTATING REACTOR

摘要

Polysilicon deposition on SiO_2 layer from SiH_4 was carried out using a fast wafer-rotating reactor. Step coverage of the trench, with diameter of 0.6μm and aspect ratio of 9, was increased with the increase in the wafer-rotation speed. The deposition rate of the wafer surface was decreased with the increase in the wafer-rotation speed. The concentrations of active intermediates produced from SiH_4 decomposition reactions, with sticking probabilities greater than about 0.1, are reduced with the increase in the wafer-rotation speed, because the gas phase reaction is suppressed. Simulation results based on some mechanisms were compared with the experimental results, and the incident fluxes of intermediates were estimated. The uniformity of coverage within an 8-inch wafer was examined.