The interface properties of 4H-SiC metal oxide semiconductor （MOS） capacitors with post-oxidation annealing （POA） in nitric oxide （NO） ambient after high temperature （1300 ℃） oxidation have been investigated ...The interface properties of 4H-SiC metal oxide semiconductor （MOS） capacitors with post-oxidation annealing （POA） in nitric oxide （NO） ambient after high temperature （1300 ℃） oxidation have been investigated using capacitance-voltage （C V） measurements. The experimental results show that the interface states density （Dit） can be obviously decreased by the POA in NO ambient （NO-POA） and further reduced with increasing POA temperature and time. In the meantime significant reduction of the interface states density and oxidation time can be achieved at the higher thermal oxidation temperature, which results in the better oxide MOS characteristics and lower production costs. The dependence of Dit on POA temperature and time has been also discussed in detail.展开更多
We study a series of（HfO2）x（Al2O3）1-x /4H-SiC MOS capacitors. It is shown that the conduction band offset of HfO2 is 0.5 e V and the conduction band offset of Hf AlO is 1.11–1.72 e V. The conduction band offsets...We study a series of（HfO2）x（Al2O3）1-x /4H-SiC MOS capacitors. It is shown that the conduction band offset of HfO2 is 0.5 e V and the conduction band offset of Hf AlO is 1.11–1.72 e V. The conduction band offsets of（Hf O2）x（Al2O3）1-x are increased with the increase of the Al composition, and the（HfO2）x（Al2O3）1-x offer acceptable barrier heights（〉 1 e V）for both electrons and holes. With a higher conduction band offset,（Hf O2）x（Al2O3）1-x/4H-SiC MOS capacitors result in a ～ 3 orders of magnitude lower gate leakage current at an effective electric field of 15 MV/cm and roughly the same effective breakdown field of ～ 25 MV/cm compared to HfO2. Considering the tradeoff among the band gap, the band offset, and the dielectric constant, we conclude that the optimum Al2O3 concentration is about 30% for an alternative gate dielectric in 4H-Si C power MOS-based transistors.展开更多
基金Project supported by the National Natural Science Foundation of China(No.61234006)the State Grid of China(No.sgri-wd-71-14-003)
文摘The interface properties of 4H-SiC metal oxide semiconductor （MOS） capacitors with post-oxidation annealing （POA） in nitric oxide （NO） ambient after high temperature （1300 ℃） oxidation have been investigated using capacitance-voltage （C V） measurements. The experimental results show that the interface states density （Dit） can be obviously decreased by the POA in NO ambient （NO-POA） and further reduced with increasing POA temperature and time. In the meantime significant reduction of the interface states density and oxidation time can be achieved at the higher thermal oxidation temperature, which results in the better oxide MOS characteristics and lower production costs. The dependence of Dit on POA temperature and time has been also discussed in detail.
基金supported by the National Natural Science Foundation of China(Grant Nos.51272202 and 61234006)the Science Project of State Grid,China(Grant No.SGRI-WD-71-14-004)
文摘We study a series of（HfO2）x（Al2O3）1-x /4H-SiC MOS capacitors. It is shown that the conduction band offset of HfO2 is 0.5 e V and the conduction band offset of Hf AlO is 1.11–1.72 e V. The conduction band offsets of（Hf O2）x（Al2O3）1-x are increased with the increase of the Al composition, and the（HfO2）x（Al2O3）1-x offer acceptable barrier heights（〉 1 e V）for both electrons and holes. With a higher conduction band offset,（Hf O2）x（Al2O3）1-x/4H-SiC MOS capacitors result in a ～ 3 orders of magnitude lower gate leakage current at an effective electric field of 15 MV/cm and roughly the same effective breakdown field of ～ 25 MV/cm compared to HfO2. Considering the tradeoff among the band gap, the band offset, and the dielectric constant, we conclude that the optimum Al2O3 concentration is about 30% for an alternative gate dielectric in 4H-Si C power MOS-based transistors.
