Hole trap analysis in SiO2/Si structures by electron tunneling

作者：M. Schmidt, H. Köster · 发表于：physica status solidi (b) · 年份：1992 · DOI：10.1002/pssb.2221740106 · 被引用次数：35 · 研究领域：Semiconductor materials and devices、Electronic and Structural Properties of Oxides、Ga2O3 and related materials

Abstract Hole trap parameters in Si/SiO2 structures are investigated by their charge relaxation after a foregoing hole trap population. A concept based on tunneling between extended Si states and localized SiO2 states is developed to explain the logarithmic time dependence, gate voltage dependence, and temperature dependence of hole trap depopulation. A positively charged hole trap level with a trap energy of E = (6.3 ± 0.2) eV above the SiO2 valence band edge is found. The corresponding value of the wave vector is |K(E)| = 6.1 nm−1 according to the two‐band approximation for the K(E) relation in the SiO2 gap. The hole trap concentration is N = 2 to 5 × 1019 cm−3 inside a small (5 nm) near‐interface region. These results are in agreement with EPR experiments and confirm that the E'‐centre (oxygen vacancy) constitutes a dominating paramagnetic defect and a hole trap.