Ga vacancies and electrical compensation in β-Ga 2 O 3 thin films studied with positron annihilation spectroscopy

We have applied positron annihilation spectroscopy to study vacancy-type defects in unintentionally doped and Si and Sn doped β-Ga 2 O 3 homoepitaxial thin films grown by metal-organic chemical vapor deposition (MOCVD). We detect Ga vacancy related defects at high concentrations in semi-insulating and highly resistive material, while conductive (ntype) material exhibits very low Ga vacancy concentrations. These findings show that Ga vacancies can act as efficient electrical compensators for n-type conductivity, but their concentrations can be suppressed by controlling the growth environment, leading to efficient n-type doping. We also note the strong anisotropy of the positron annihilation signals and give recommendation for presenting positron data obtained in β-Ga 2 O 3 .

Keywords

Compensation, Defect, Gallium oxide, Positron annihilation spectroscopy, Vacancy

DOI

10.1117/12.2518888

Citation

Tuomisto , F , Karjalainen , A , Prozheeva , V , Makkonen , I , Wagner , G & Baldini , M 2019 , Ga vacancies and electrical compensation in β-Ga 2 O 3 thin films studied with positron annihilation spectroscopy . in D J Rogers , F H Teherani & D C Look (eds) , Oxide-Based Materials and Devices X . , 1091910 , Proceedings of SPIE , vol. 10919 , SPIE , pp. 1-8 , Oxide-Based Materials and Devices , San Francisco , California , United States , 03/02/2019 . https://doi.org/10.1117/12.2518888

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-201906203934

Collections

[article-cris] Perustieteiden korkeakoulu / SCI

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