Theoretical and Experimental Demonstration of Electronic State of GeO_2

摘要

The transition levels of oxygen vacancy (Vo) in GeO_2 with different charge state are calculated by first principle method. The formation energy of GeO_2 indicates there is a (+2/0) fix charge state in bulk GeO_2. The (+1/0) transition level near Ge valence band maximum which shows positive charge trap of GeO_2. We demonstrate a Ge MOS capacitor with thermal oxidation. The hysteresis of CV shows a negative V_(fb) shift which corresponds to the positive charge trap as theoretical calculation implies.