Electronic properties of Si/Si-Ge Alloy/Si(100) heterostructures formed by ECR Ar plasma CVD without substrate heating

摘要

By using our low-energy Ar plasma enhanced chemical vapor deposition (CVD) at a substrate temperature below 100 degrees C during plasma exposure without substrate heating, modulation of valence band structures and infrared photoluminescence can be observed by change of strain in a Si/strained Si0.4Ge0.6/Si(100) heterostructure. For the strained Si0.5Ge0.5 film, Hall mobility at room temperature was confirmed to be as high as 660 cm(2) V-1 s(-1) with a carrier concentration of 1.3 x10(18) cm(-3) for n-type carrier, although the carrier origin was unclear. Moreover, good rectifying characteristics were obtained for a p(+)Si/nSi(0.5)Ge(0.5) heterojunction diode. This indicates that the strained Si-Ge alloy and Si films and their heterostructures epitaxially grown by our low energy Ar plasma enhanced CVD without substrate heating can be applicable effectively for various semiconductor devices utilizing high carrier mobility, built-in potential by doping and band engineering.