Abstract
Schottky barrier diodes were produced from β-Ga2O3 epitaxial wafers for X-ray detection. The devices were fabricated from a bulk Sn-doped (001) n-type Ga2O3 substrate with a Si-doped epitaxial layer grown by hydride vapor phase epitaxy (HVPE). The Schottky diodes were fabricated with circular Schottky metal contacts with diameters ranging from 50 to 1500 µm and square metal contacts ranging from 100×100 µm2 to 1600×1600 µm2. The devices were characterized for their electrical performance first including forward current-voltage (FIV), reverse current-voltage (RIV), and capacitance-voltage (CV) measurements. The best device showed a breakdown voltage of -804 V and the devices tested had an average ideality of 1.12 eV. The devices exhibited a clear response to X-rays even at zero bias and a linear response of detector signal to the X-ray dose rate. The sensitivity and the lowest limit of detection for X-ray by Ga2O3 epitaxial Schottky detectors were discussed and determined.
