GESN ALLOYS AND ORDERED PHASES WITH DIRECT TUNABLE BANDGAPS GROWN DIRECTLY ON SILICON

摘要

A method for depositing an epitaxial Ge-Sn layer on a substrate in a CVD reaction chamber includes introducing into the chamber a gaseous precursor comprising SnD4 under conditions whereby the epitaxial Ge-Sn layer (a-d) is formed on the substrate The gaseou precursor comppses SnD4 and high purity H2 of about 15-20% by volume The gaseous precursor is introduced at a temperature in range of about 250oC to about 350oC Using the process device-quality Sn-Ge material with tunable bandgaps can be grown directl on Si substrates