Demonstration of Large-Size Vertical Ga2O3Schottky Barrier Diodes

Abstract

Large-size vertical β-Ga2O3 Schottky barrier diodes (SBDs) with various device areas were demonstrated on a Si-doped n-type drift layer grown by hydride vapor phase epitaxy (HVPE) on bulk Sn-doped (001) n-type β-Ga2O3 substrate. In this letter, the devices have two circular contacts with a diameter of 1500 and 500 μm and two square contacts with dimensions of 1600 × 1600 μm2 and 800 × 800 μm2, corresponding to the area of 0.2 × 10-2 cm2 (the smallest device), 0.6 × 10-2, 1.8 × 10-2, and 2.6 × 10-2 cm2 (the largest device). The breakdown voltage (BV) was determined to be -261 V for the largest device and -427 V for the smallest device. Also, the ideality factor (η) of vertical Ga2O3 SBDs with different device areas exhibited the same value of 1.07, except for the largest device area of 2.6 × 10-2 cm2 with an ideality factor of 1.21. At an applied forward bias of VF= 2 V, the specific on-state resistance (RonA) of all the Ga2O3 SBDs remains relatively low with values ranging from 1.43 × 10-2 Ω cm2 to 7.73 × 10-2 Ω cm2. The measured turn-on voltage (Von) of all the SBDs remains low with a narrow distribution.