Growth and band gap of strained 〈110〉 Si1−xGex layers on silicon substrates by chemical vapor deposition

We report chemical vapor deposition growth of strained Si1−xGex alloy layers on 〈110〉 Si substrates. Compared to the same growth conditions on 〈100〉 substrates, a slightly lower Ge composition and a much lower growth rate was observed. From photoluminescence measurements, the band gap of these films for 0.16≤x≤0.43 is evaluated and compared to theory. Finally, a surprisingly large ‘‘no-phonon’’ replica line strength ratio was observed as compared with that observed in 〈100〉 layers.