The effects of oxidation on strain relaxation in Si1-xGe x layers on silicon substrates were investigated. Si 1-xGex layers, with different Ge fractions (x=0.15 and 0.3), were grown on chemically cleaned silicon substrates by an ultrahigh vacuum chemical vapor deposition process. Oxidation at 800 and 900 °C under O 2 ambient in a tube furnace resulted in the production of silicon oxide layers on top and a Ge-rich region in the Si1-xGex films. It was observed that the oxidation of Si0.85 Ge0.15 films at 900 °C produced the relaxation of the misfit strain in the remnant Si 1-xGex layer and the increase in strain in the Ge pile-up layer with increasing oxidation time, while the oxidation at 800 °C produced no changes in the misfit strain in the Si1-xGex layers. The oxidation of Si0.70 Ge0.30 films at 800 °C showed the relaxation of the misfit strain in the remnant Si1-xGex layer with the accumulation of stain in the Ge pile-up layer. However, the oxidation of Si0.70 Ge0.30 layers at 900 °C exhibited the strain relaxation in the Ge pile-up layer after the Ge pile-up was extended into the remaining Si 1-xGex layer, with the formation of misfit dislocations at the interface between the remaining Si1-xGex and Si substrate.
Bibliographical noteFunding Information:
This work was financially supported by the IT R&D program of MKE/KEIT (Grant No. KI002083, Next-Generation Substrate Technology for High Performance Semiconductor Devices and 10035320, Development of novel 3D stacked devices and core materials for the next generation flash memory).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering
- Materials Chemistry