Insulating Ga_2O_3 layer formation at SiO_2/β-Ga_2O_3 interface during oxygen annealing at 1000°C and its impact on Ga_2O_3 MOS interface characteristics

摘要

Significant change of carrier density in the surface region of Ga_2O_3 in SiO_2/β-Ga_2O_3 MOS capacitors by O_2 annealing at 1000°C was indicated to result in both the increase of the effective dielectric layer thickness and the formation of a lower Nd region with the depth of ～ a few hundreds of nanometers. Such change of the interface electrical structure may be related to the formation of MOS interface with significantly reduced Dit. This work was partly done in the collaboration with JST-LCS. References: [1] E. Suzuki et al., 2018 Spring Meeting of JSAP, 12a-M121-5. [2] T. Oshima et al., JJAP 52, 051101(2013).