Investigation of Degradation of Inversion Channel Mobility of SiC MOSFET due to the Increase of Channel Doping

Tetsuo Hatakeyama; Takatoshi Watanabe; Junji Senzaki; Makoto Kato; Kenji Fukuda; Takashi Shinohe; Kazuo Arai

doi:10.4028/www.scientific.net/MSF.483-485.829

Paper Titles

Analysis of Low On-Resistance in 4H-SiC Double-Epitaxial MOSFET
p.813

Low On-Resistance in Normally-Off 4H-SiC Accumulation MOSFET
p.817

Short-Channel Effects in 4H-SiC MOSFETs
p.821

Performance of SiC Cascode Switches with Si MOS Gate
p.825

Investigation of Degradation of Inversion Channel Mobility of SiC MOSFET due to the Increase of Channel Doping
p.829

Field Effect Mobility in n-Channel Si Face 4H-SiC MOSFET with Gate Oxide Grown on Aluminium Ion-Implanted Material
p.833

High Field Effect Mobility in 6H-SiC MOSFET with Gate Oxides Grown in Alumina Environment
p.837

High Field Effect Mobility in Si Face 4H-SiC MOSFET Made on Sublimation Grown Epitaxial Material
p.841

Modeling of Lattice Site-Dependent Incomplete Ionization in α-SiC Devices
p.845

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Investigation of Degradation of Inversion Channel Mobility of SiC MOSFET due to the Increase of Channel Doping

Abstract:

This paper reports on the degradation of inversion channel mobility of SiC MOSFET caused by the increase of channel doping. SiC MOSFETs were fabricated on three wafers, the doping concentrations of the epitaxial layer of which were 16 10 2× cm-3 (sample A), 17 10 2× cm-3 (sample B) and 17 10 4× cm-3 (sample C). The field effect mobility sharply decreases as the doping concentration increases. Hall mobility measurements have been done to investigate the degradation of the mobility due to doping. The measurement of sample A shows that, as a consequence of the decrease of the free carrier density due to MOS interface traps, the Hall mobility is as much as a factor of ten higher than the field effect mobility. In contrast, in regard to the measurement of sample B and sample C, we encountered unstable Hall voltage and could not obtain reproducible results. This implies that such high-density traps are generated that a channel disappears in the higher-doping samples.