High work function MoO2 and ReO2 contacts for p-type Si and GaN by a room-temperature non-vacuum process

Abstract

High work function molybdenum (Mo) and rhenium (Re) di-oxides were studied without vacuum and thermal process to investigate the contact properties on p-type Si and GaN semiconductors. Polyvinyl alcohol (5 wt% PVA) was used as a binder for the metal oxide powder. ReO2 showed lower electrical resistivity < 0.023 +/- 0.004 Omega cm and better contact characteristics compared to MoO2. Ohmic contacts were formed easily on p-type Si (rho = 9.77 Omega cm) using ReO2 and MoO2. The metal oxide/semiconductor Schottky diodes fabricated by forming contacts on n-type Si (rho = 2.44 Omega cm) were investigated by comparing diode parameters indicating different contact barrier properties of metal oxides. As a wide energy bandgap semiconductor, p-type GaN was utilized to investigate metal oxide contact properties on a high work function semiconductor. Ohmic contact on p-type GaN was obtained using ReO2 after the surface treatment by boiling aqua regia.