High resistivity halide vapor phase homoepitaxial β-Ga_2O_3 films co-doped by silicon and nitrogen

摘要

Semi-insulating halide vapor phase epitaxial beta-Ga2O3 films without intentional dopants introduced during growth are demonstrated. The sheet resistance measured in the 340-480 K range yielded 268-134 K Omega/square 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 similar to 4.4 V) estimated to be 10(14) 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 x 10(15) cm(-3) and an N concentration of about 2 x 10(17) cm(-3) were detected, suggesting that N acceptors compensated Si donors to result in a nearly intrinsic beta-Ga2O3 film. Photoionization spectroscopy suggested the presence of a deep acceptor-like level located at E-c -0.23 eV.