High resistivity halide vapor phase homoepitaxial β-Ga2O3 films co-doped by silicon and nitrogen.

Semi-insulating halide vapor phase epitaxial β-Ga₂O₃ films without intentional dopants introduced during growth are demonstrated. The sheet resistance measured in the 340–480 K range yielded 268–134 kΩ/◻ and an activation energy of 0.81 eV. Room temperature capacitance-voltage measurements at 1 MHz showed evidence of an ultra-low free carrier concentration n-type film with a free carrier concentration near flatband (V_FB ∼ 4.4 V) estimated to be <10¹⁴ cm⁻³, resulting in a high breakdown voltage of 2380 V (3.18 MV/cm) measured on a lateral diode without field termination. Secondary ion mass spectroscopy did not reveal Fe compensating species; however, an average Si concentration of about 5 × 10¹⁵ cm⁻³ and an N concentration of about 2 × 10¹⁷ cm⁻³ were detected, suggesting that N acceptors compensated Si donors to result in a nearly intrinsic β-Ga₂O₃ film. Photoionization spectroscopy suggested the presence of a deep acceptor-like level located at E_c −0.23 eV. [ABSTRACT FROM AUTHOR]