Scattering Mechanisms in Silicon Carbide MOSFETs with Gate Oxides Fabricated Using Sodium Enhanced Oxidation Technique

Vinayak Tilak; Kevin Matocha; Greg Dunne; Fredrik Allerstam; E.Ö. Sveinbjörnsson

doi:10.4028/www.scientific.net/MSF.600-603.687

Paper Titles

TEM Observation of SiO₂/4H-SiC Hetero Interface
p.671

Influence of Metallization Annealing on Channel Mobility in 4H-SiC MOSFET on Carbon Face
p.675

Enhanced Channel Mobility in 4H-SiC MISFETs by Utilizing Deposited SiN/SiO₂ Stack Gate Structures
p.679

Anomalously High Channel Mobility in SiC-MOSFETs with Al₂O₃/SiO_x/SiC Gate Structure
p.683

Scattering Mechanisms in Silicon Carbide MOSFETs with Gate Oxides Fabricated Using Sodium Enhanced Oxidation Technique
p.687

High Channel Mobility of MOSFET Fabricated on 4H-SiC (11-20) Face Using Wet Annealing
p.691

High Channel Mobility of 4H-SiC MOSFET Fabricated on Macro-Stepped Surface
p.695

Improvement of Electron Channel Mobility in 4H SiC MOSFET by Using Nitrogen Implantation
p.699

Reduction of Interface Traps and Enhancement of Channel Mobility in n-Channel 6H-SiC MOSFETs by Irradiation with Gamma-Rays
p.703

HomeMaterials Science ForumMaterials Science Forum Vols. 600-603Scattering Mechanisms in Silicon Carbide MOSFETs...

Scattering Mechanisms in Silicon Carbide MOSFETs with Gate Oxides Fabricated Using Sodium Enhanced Oxidation Technique

Abstract:

The improvement of the SiC-SiO2 interface has been the main focus of research in SiC MOSFET technology due to the presence of high density of interface traps (Dit) leading to poor threshold voltage temperature stability and poor mobility. In SiC MOSFETs with the gate oxide grown in the presence of sodium, known as sodium enhanced oxidation(SEO), a lower Dit and higher field effect mobility has been observed [1]. Hall effect measurements were performed from 125°K-225°K on such MOSFET samples. The Hall measurements were made as a function of temperature for various sheet charge concentrations. The sheet charge density was measured as a function of gate bias at 225°K and there is very little trapped charge in the sample with oxide grown by SEO while about 50 % of the total charge is trapped in a sample with N2O grown oxide annealed in NO. In samples with oxide grown by SEO, there is a monotonic increase in mobility with sheet charge density and the mobility also increases with temperature. This is an indication that the main scattering mechanism is Coulomb scattering in this regime.