Study of contact resistance of α-Ga2O3 on m-plane sapphire substrate with respect to Sn concentration using the circular transfer length method

In this study, the Sn concentration dependence of the sheet and contact resistances of the m-plane α-Ga2O3 were analyzed and the corresponding current mechanism was determined. The measurements were performed using samples by systematically varying the Sn concentration from 1 × 1017 to 1 × 1019 cm–3. The circular transfer length method pattern was then fabricated, and the sheet and contact resistances were calculated. The Sn concentration dependence was determined for both the sheet and contact resistances. The thermionic field emission model was applied as a current mechanism for the contact resistance, and its results were compared with the values calculated using the Schottky barrier as a parameter. The effect of light illumination on the contact resistance was also analyzed.