Insights into ultraviolet-induced electrical degradation of thermally grown SiO{sub 2}/4H-SiC(0001) interface
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)
- Power Electronics R and D Unit, ROHM CO., LTD., 21 Saiin Mizosaki-cho, Ukyo-ku, Kyoto 615-8585 (Japan)
The harmful impact of ultraviolet (UV) light irradiation on thermally grown SiO{sub 2}/4H-SiC structures was investigated by means of electrical measurements of metal-oxide-semiconductor (MOS) capacitors. Unlike Si-based MOS devices, significant electrical degradation, such as positive flatband voltage (V{sub FB}) shift and hysteresis in the capacitance-voltage (C-V) curves of SiC-MOS capacitors was induced by UV irradiation with a low-pressure mercury lamp. The interfacial fixed charge density increased with UV-irradiation (22.6 mW/cm{sup 2} for 16 h) to 1.7 × 10{sup 12} cm{sup −2}, which was an order of magnitude larger than that of the as-grown SiO{sub 2}/SiC interface. A detailed study based on single wavelength solid-state UV lasers revealed that there was a threshold photon energy at around 5 eV and a moderate dependence of UV-induced degradation on temperature. These experimental findings imply that pre-existing inactive defects accumulated at the thermally grown SiO{sub 2}/SiC interface were transformed to active carrier traps with high-energy UV irradiation through transparent SiO{sub 2} layers.
- OSTI ID:
- 22257143
- Journal Information:
- Applied Physics Letters, Vol. 104, Issue 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fabrication of SiO{sub 2}/4H-SiC (0001) interface with nearly ideal capacitance-voltage characteristics by thermal oxidation
Study of SiO{sub 2}/4H-SiC interface nitridation by post-oxidation annealing in pure nitrogen gas