GAS SOURCE MOLECULAR-BEAM EPITAXY OF SI AND SIGE USING SI2H6 AND GEH4

Gas source molecular-beam epitaxy (MBE) has been studied as a low-temperature Si and SiGe epitaxial method. Specular single-crystalline silicon films were successfully grown by the gas source Si MBE technique at a substrate temperature of about 650-degrees-C. N-type doping was carried out using PH3 gas as a dopant and the maximum electron concentration of 2.9 x 10(19) cm-3 was obtained. Furthermore, p-type doping using B2H6 gas was carried out for the first time and the maximum hole concentration of 9.5 x 10(17) cm-3 was successfully achieved. The SiGe alloy layer was also grown by the gas source MBE technique using GeH4 as a Ge source gas. The Ge concentration of the sample could be precisely controlled by the molar fraction of Ge in supply and it was increased up to 0.30 with increasing the gas ratio of GeH4 to Si2H-6.