The mechanism for the stress-relaxation in the Ge condensation induced by H+ irradiation-assisted oxidation method was investigated. Relaxation ratio of Si0.7Ge0.3 (thickness: 28 nm) formed by medium dose H+ irradiation (5 × 1015 cm- 2) and oxidation at 1100 °C was limited to 35%. Post-annealing (1200 °C) improved this value significantly (70%), though defect density was found to be kept at low density (< 106 cm- 2). However, the height of cross hatches was increased (from 0.6 nm to 4.1 nm) after post-annealing. Based on these results, local-area slipping model was proposed, where slipping at SiGe/SiO2 interface of local areas surrounded by cross hatches enhanced stress-relaxation. This model could quantitatively explain the stress-relaxation enhanced by combination of H+ irradiation, oxidation-induced Ge condensation, and post-annealing.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry