Effect of formation temperature on quality of gate dielectric on germanium substrate

Germanium metal-insulator-semiconductor (MIS) structure with HfO2/Al2O3/GeO2 gate stack have been demonstrated to exhibit good performance. In this work, the effect of formation temperature of the gate stack on the quality of the gate dielectric is investigated. It is found that the higher plasma oxidation temperature helps the GeO2 formation and less interface states. But the higher deposition temperature of the ALD high-k films may degrade the interface and result in higher leakage current.