Ge doping of α-Ga2O3 thin films via mist chemical vapor deposition and their application in Schottky barrier diodes

We performed Ge doping of alpha-Ga(2)O(3 )thin films grown on m-plane sapphire substrates using mist chemical vapor deposition. Although the typical growth rate was high at 4 mu m/h, the resultant alpha-Ga(2)O(3 )thin films exhibited high crystallinity. We controlled the carrier density in the range of 8.2 x 10(16)-1.6 x 10(19) cm(-3) using bis[2-carboxyethylgermanium(IV)]sesquioxide as the Ge source. The highest mobility achieved was 66 cm2 V-1 s(-1) at a carrier concentration of 6.3 x 10(17) cm(-3). Through secondary ion mass spectrometry analysis, a linear relationship between the Ge concentration in the alpha-Ga2O3 thin films and the molar ratio of Ge to Ga in the source solution was established. The quasi-vertical Schottky barrier diode fabricated using the Ge-doped alpha-Ga(2)O(3 )thin films exhibited an on-resistance of 7.6 m Omega cm(2) and a rectification ratio of 10(10). These results highlight the good performance of the fabricated device and the significant potential of Ge-doped alpha-Ga(2)O(3 )for power-device applications. (c) 2024 Author(s).