We fabricated fully strained Si 0.77 Ge 0.23 epitaxial layers on Si substrates and investigated their strain relaxation behaviors under dry oxidation and the effect of oxidation temperatures and times. After the oxidation process, a Ge-rich layer was formed between the oxide and the remaining Si 0.77 Ge 0.23 layer. Using reciprocal space mapping measurements, we confirmed that the strain of the Si 0.77 Ge 0.23 layers was efficiently relaxed after oxidation, with a maximum relaxation value of ~ 70% after oxidation at 850 °C for 120 min. The surface of Si 0.77 Ge 0.23 layer after strain relaxation by dry oxidation was smoother than a thick Si 0.77 Ge 0.23 layer, which achieved a similar strain relaxation value by increasing the film thickness. Additionally, N2 annealing was performed in order to compare its effect on the relaxation compared to dry oxidation and to identify relaxation mechanisms, other than the thermally driven ones, occurring during dry oxidation.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)