Interface behaviour and electrical performance of ruthenium Schottky contact on 4H-SiC after argon annealing

Kinnock V Munthali,Sergio M M Coelho,F Danie Auret,Chris Theron

doi:10.1007/s12034-015-0904-1

Kinnock V Munthali, Sergio M M Coelho + Show 2 more

Open Access

https://doi.org/10.1007/s12034-015-0904-1

Copy DOI

Abstract

Rutherford backscattering spectrometry (RBS) analysis, carried out at various annealing temperatures, of a thin film of ruthenium on n-type four-hexagonal silicon carbide (4H-SiC) showed the evidence of ruthenium oxidation, ruthenium silicide formation and diffusion of ruthenium into silicon carbide starting from an annealing temperature of 400°C. Ruthenium oxidation was more pronounced, and ruthenium and silicon interdiffusion was very deep after annealing at 800°C. Raman analysis of some samples also showed ruthenium silicide formation and oxidation. The Schottky barrier diodes showed very good linear capacitance–voltage characteristics and excellent forward current–voltage characteristics, despite the occurrence of the chemical reactions and interdiffusion of ruthenium and silicon at ruthenium–silicon–carbide interface, up to an annealing temperature of 800°C.

Highlights

There is renewed interest by researchers in silicon carbide (SiC), owing to the fact that it has superior properties of a large band gap, a high breakdown electric field, high thermal conductivity, high saturation carrier velocity and high mechanical strength when compared with silicon
Four-hexagonal silicon carbide (4H-SiC) and six-hexagonal silicon carbide (6H-SiC) have very similar physical, chemical and electrical properties, 4HSiC exhibits a higher electron mobility on the c-axis when compared with 6H-SiC.[1]
Electrical performance of the Schottky barrier diodes (SBDs) was gauged from parameters such as SBH, ideality factor, reverse-saturation current and series resistance of the SBDs which were extracted from current–voltage (I –V ) and capacitance–voltage (C–V ) characteristics of the diode

Summary

Introduction

There is renewed interest by researchers in silicon carbide (SiC), owing to the fact that it has superior properties of a large band gap, a high breakdown electric field, high thermal conductivity, high saturation carrier velocity and high mechanical strength when compared with silicon. These properties make SiC an ideal material for the fabrication of electronic devices which can operate in extreme environments. At such extreme operating temperatures, chemical reaction and diffusion of elements at the interface of the Schottky contact and SiC are bound to happen The occurrence of these processes may lead to the electrical-performance degradation of the device. Electrical performance of the SBDs was gauged from parameters such as SBH, ideality factor, reverse-saturation current and series resistance of the SBDs which were extracted from current–voltage (I –V ) and capacitance–voltage (C–V ) characteristics of the diode

Experimental

Results and discussion

Conclusion