Presentation Information
[17a-PA3-3]Surface Decomposition and Re-oxidation of β-Ga2O3(01) Surface Observed via STM and TOF-ESD
〇Arifumi Okada1, Junya Okabe1 (1.Kyoto Inst. Tech.)
Keywords:
ultrahigh vacuum,wide-gap semiconductor,surface observation
Implementation of β-Ga2O3-based next-generation power devices needs development of heterostructure construction with other materials. In order to obtain high-quality device with suppressed interfacial defects, surface morphology and chemical structure of the β-Ga2O3 substrate are important. Here we demonstrate a combined study with STM and TOF-ESD to clarify the surface chemical structure of β-Ga2O3. After degassing, the sample was annealed at 800-900 C for 20 min. O2 was introduced using a variable leak valve. STM was performed at room temperature. The TOF-ESD measurement was performed using a home-built system. In the TOF-ESD spectra obtained on the annealed surface, several components were observed and attributed to H+, O+, Ga2O+ and some fragments. After O2 exposure, Ga2O+ spectral component was disappeared. These behaviors were related to thermal decomposition and re-oxidation of β-Ga2O3. These results were in consistent with STM observations.