Crystal log raphic orientation engineering in silicon-on-insulator substrates

摘要

A bilayer silicon-on-insulator film was engineered to locally convert the crystallographic orientation from (100) to (110). The initial bilayer film is composed of a first 50 nm thick (110) oriented Si surface layer, above a second 20 nm thick (100) oriented Si underlayer. The bilayer film was elaborated using hydrophobic bonding to ensure an atomic contact between the two layers without any intermediate oxide. A local and deep-amorphization was developed by ion implantation to amorphize the (100) oriented Si underlayer, conserving also a partially crystalline (110) oriented surface layer. After such a deep amorphization, a solid phase epitaxy regrowth was performed at 900 ℃. Transmission electron microscopy observations confirm that the partially crystalline surface layer acts as a seed for the epitaxial regrowth of the amorphized areas through the hydrophobic bonding interface. Thus, the orientation is locally converted from (100) to (110) in the underlayer, which could lead to the elaboration of hybrid films over a continuous insulating oxide that are mandatory for high performance electronic devices.