Influence of Phosphorous Auto-Doping on the Characteristics of SiO2/SiC Gate Dielectrics
| Autor: | Alton B. Horsfall, Robin. F. Thompson, R.A.R. Young, B.J.D. Furnival, Craig T. Ryan, D. T. Clark, E.P. Ramsay, A.E. Murphy, Ming Hung Weng, Dave A. Smith |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
business.industry Annealing (metallurgy) Mechanical Engineering Doping Gate dielectric Oxide Electrical engineering Time-dependent gate oxide breakdown Dielectric Condensed Matter Physics chemistry.chemical_compound chemistry Mechanics of Materials Gate oxide Optoelectronics General Materials Science Wafer business |
| Zdroj: | Materials Science Forum. :492-495 |
| ISSN: | 1662-9752 |
| Popis: | We present the influence of phosphorous auto-doping on the characteristics of the oxide interface in 4H-SiC following high temperature gate oxide annealing. IV characteristics show no evidence of direct tunnelling breakdown; however Fowler Nordheim (F-N) conduction is observed in high electric field with the oxides able to sustain >10MV/cm. Capacitance Voltage data show DIT 12 eV-1cm-2 close to the conduction band edge after POA, with undoped samples demonstrating DIT below 5x1011 eV-1cm-2. Photo CV data indicates smaller flat band voltage shifts of 0.6V at midpoint for the undoped samples, in comparison to 0.9V for the phosphorous doped devices. Temperature and bias stress tests at 200°C showed marginal hysteresis (0.3V) in both wafers. Reliability of time-dependent constant current and constant voltage characteristics revealed higher TDDB lifetimes in the undoped wafer. We conclude that the unintentional incorporation of phosphorous into the gate stack as a result of high temperature POA of the doped field oxide leads to a variation in flat band shift, higher DIT, and lower dielectric reliability. |
| Databáze: | OpenAIRE |
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