Chip-size formation of high-mobility Ge strips on SiN films by cooling rate controlled rapid-melting growth

Abstract

High-quality Ge-on-insulators (GOIs) are essential structures for high-performance transistors on an Si platform. We developed a rapid-melting-growth process for amorphous Ge (a-Ge) by optimizing the cooling rate and the underlying insulating materials. The effects of the solidification process for molten Ge on hole generation and spontaneous nucleation in Ge were determined. In addition, nucleation in the a-Ge matrix was found to be drastically suppressed by substituting SiO2 underlayers with SiN underlayers. By combining high cooling rates (10.5-11.5 °Cs-1) and SiN underlayers, we obtained ultra-long single crystal GOI strips (1 cm) with high hole mobilities (> 1000 cm2V-1s -1). This chip-size formation of high-quality GOI will facilitate the development of advanced high-speed Ge-based devices. © 2011 American Institute of Physics.