Fabrication of novel double-hetero-epitaxial SOI structure Si/γ-Al_2O_3/Si

摘要

In this paper, we report the fabrication of Si-based double-hetero-epitaxial silicon on insulator (SOI) structure Si/γ-Al_2O_3/Si. Firstly, single crystalline γ-Al_2O_3(100) insulator films were grown epitaxially on Si(100) using the sources of TMA (Al(CH_3)_3) and O_2 by very low-pressure chemical vapor deposition. Afterwards, Si(100) epitaxial films were grown on γ-Al_2O_3 (100)/Si(100) epi-substrates using a chemical vapor deposition method similar to the silicon on sapphire epitaxial growth. The Si/γ-Al_2O_3/Si SOI materials are characterized in detail by reflect high-energy electron diffraction, X-ray diffraction and Auger energy spectrum (AES) techniques. The insulator layer of γ-Al_2O_3 has an excellent dielectric property. The leakage current is less than 1 x 10~(-10) A/cm~2 when the electric field is below 1.3 MV/ cm. The Si film grown on γ-Al_2O_3/Si epi-substrates was single crystalline. Meanwhile, the AES depth profile of the SOI structure shows that the composition of γ-Al_2O_3 film is uniform, and the carbon contamination is not observed. Additionally, the γ-Al_2O_3/Si epi-substrates are suitable candidates as a platform for a variety of active layers such as GaN, SiC and GeSi. It shows a bright future for microelectronic and optical electronics applications.