INVESTIGATION ON THE GROWTH-RATE ENHANCEMENT BY GE DURING SIGE ALLOY DEPOSITION BY CHEMICAL VAPOR-DEPOSITION

The desorption of deuterium from clean and Ge-covered Si(100) surfaces has been studied using temperature-programmed desorption. The Ge/Si(100) surfaces were prepared using the dissociative adsorption of digermane on Si(100). The presence of Ge on Si(100) dramatically lowers the deuterium (or hydrogen) desorption temperature. The desorption maxima shift to lower temperature with increasing Ge coverage until a new low-temperature desorption state becomes dominant. The lowering of the deuterium desorption energies due to the presence of Ge on the Si(100) surface is used to explain the acceleration in growth rate observed during GexSi1-x, alloy growth by chemical vapor deposition upon the introduction of germane to the Si source gas.