Electronic Properties of Thin HfO₂Films Fabricated by Atomic Layer Deposition on 4H-SiC

Abstract

Applicability of thin HfO2 films as gate dielectric for SiC MOSFET transistor is reported. Layers characterisation was done by means of atomic force microscopy and scanning electron microscopy, spectroscopic ellipsometry and C-V and I-V measurements of MIS structures. High permittivity dielectric layers were deposited using atomic layer deposition. Investigation showed high value of = 15 and existence of high density surface states (5 10 12 eV -1 cm -2 ) on HfO2/SiC interface. High leakage current is caused probably due to low conduction band offset between hafnium oxide and silicon carbide.