Selective growth of silicon-germanium alloys by atmospheric-pressure chemical vapor deposition at low temperatures

Dichlorosilane and germane were used to grow silicon-germanium alloys at temperatures as low as 550°C at atmospheric pressure. The silicon-germanium alloy composition was varied over the range 15%-44%. Films containing high Ge mole fractions were grown at a temperature of 625°C and below and exhibit smooth surface morphology. Silicon-germanium/silicon multilayers with abrupt heterointerfaces have been achieved. Selective growth of silicon-germanium on oxide patterned silicon wafers was also demonstrated. A significant feature of the selective deposition is the lack of faceting at the oxide sidewall, which has been commonly observed in high-temperature silicon growth.