TY - GEN
T1 - Scattering mechanisms in silicon carbide MOSFETs with gate oxides fabricated using sodium enhanced oxidation technique
AU - Tilak, Vinayak
AU - Matocha, Kevin
AU - Dunne, Greg
AU - Allerstam, Fredrik
AU - Sveinbjornsson, Einar O.
PY - 2009
Y1 - 2009
N2 - 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.
AB - 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.
KW - Hall effect
KW - Interface trap density
KW - Oxidation techniques
KW - SiC MOSFET
UR - https://www.scopus.com/pages/publications/63849140351
U2 - 10.4028/www.scientific.net/msf.600-603.687
DO - 10.4028/www.scientific.net/msf.600-603.687
M3 - Conference contribution
SN - 9780878493579
T3 - Materials Science Forum
SP - 687
EP - 690
BT - Silicon Carbide and Related Materials 2007
A2 - Suzuki, Akira
A2 - Okumura, Hajime
A2 - Fukuda, Kenji
A2 - Nishizawa, Shin-ichi
A2 - Kimoto, Tsunenobu
A2 - Fuyuki, Takashi
PB - Trans Tech Publications Ltd
T2 - 12th International Conference on Silicon Carbide and Related Materials, ICSCRM 2007
Y2 - 14 October 2007 through 19 October 2007
ER -