By using our low-energy Ar plasma enhanced chemical vapor deposition (CVD) at a substrate temperature below 100 °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 cm2 V−1 s−1 with a carrier concentration of 1.3×1018 cm−3 for n-type carrier, although the carrier origin was unclear. Moreover, good rectifying characteristics were obtained for a p+Si/nSi0.5Ge0.5 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.
- Heteroepitaxial growth
- Plasma chemical vapor deposition
- pn junction diode
- Silicon-germanium alloy
- Valence band