Passivation of InGaAs using in situ molecular beam epitaxy Al_2O_3/HfO_2 and HfAIO/HfO_2

摘要

In_(0.2)Ga_(0.8)As was effectively passivated using in situ molecular beam epitaxy deposited Al_2O_3/HfO_2 and HfO_2-Al_2O_3(HfAlO)/HfO_2- HfO_2 3 ML (monolayer) thick was epitaxially grown on InGaAs, as monitored by reflection high-energy electron diffraction. Al_2O_3 3 nm thick and Hf AlO 4 nm thick were used to cap 3 ML epitaxial HfO_2 due to their superior thermal stability up to 800 ℃. Well-behaved capacitance-voltage characteristics with small capacitance dispersion between 10 and 500 kHz were obtained in both Al_2O_3/HfO_2/InGaAs/GaAs and HfAlO/HfO_2/InGaAs/GaAs, with the capacitance effective thickness values of the dielectrics being 1.46 and 1.18 nm, respectively. Particularly, HfAIO/HfO_2/InGaAs/GaAs exhibited low leakage current density (2.9 × 10~(-4) A/cm~2) at |V_G-V_(FB)| = 1, good thermal stability up to 800 ℃, and an equivalent oxide thickness of 1 nm.