Fabrication of high-hole-mobility germanium-on-insulator wafers through an easy method

Abstract

In this work, an easy method for fabricating germanium on insulator (GeOI) was demonstrated through epitaxy process (the growth of Ge on silicon wafer), benzocyclobutene bonding, and film transfer. The method is highly reliable for the fabrication of GeOI, which is a complete 2 inch wafer with homogeneous and excellent material quality. Moreover, atomic force microscopy (AFM), transmission electron microscopy (TEM), and Raman spectroscopy showed that GeOI exhibits good surface and high crystal quality. GeOI has a good interface between transferred Ge and insulator because of the protective layer of SiO2 on Ge before bonding. Furthermore, a back-gate p-type metal–oxide–semiconductor field-effect transistors (MOSFET) based on GeOI showed an excellent performance due to good interface and high-quality Ge channel. A peak field-effect hole mobility as high as 332.6 cm2/V·s was obtained, which is close to that of a best pseudo-MOSFET based on GeOI by Smart Cut™ (400 cm2/V·s).