Modified GSMBE for higher growth rate and non-selective growth

Gas source molecular beam epitaxy (GSMBE) is a versatile tool For epitaxial growth of Si and SiGe from hydride precursors offering control on the atom ic level, low thermal budget, a host of in-situ surface diagnostic tools, a nd possibility of selective epitaxial growth (SEG). However, the technique suffers from a much smaller growth rate in comparison to chemical vapour de position (CVD) or solid source MBE. Where a process requires non-selective epitaxial growth (NSEG), the large contrast between growth rates over silic on and SiO2 surfaces make it impractical. These deficiencies are overcome b y addition of a pum pi ng system with managed throughput thus allowing the system to be operated in a new ultra low pressure CVD (ULPCVD) mode as well as the conventional GSMBE mode. The modified system call achieve growth ra te in excess of 0.5 mum/h and Cull NSEG in the ULPCVD mode while maintainin g all the capability and advantages of GSMBE mode. The materials and struct ures an characterised and are shown to be better in many respects compared with those grown under conventional GSMBE. (C) 2001 Elsevier Science B.V. A ll rights reserved.