(100) Plane β -Ga 2 O 3 Flake Based Field Effect Transistor and Its Hydrogen Response

2-dimensional (100) plane β phase Ga 2 O 3 ( β -Ga 2 O 3 ) flake based field effect transistor (FET) was fabricated, and its electrical characteristics was analyzed. The (100) plane β -Ga 2 O 3 flake was mechanically exfoliated from the side wall of 2 ¯ 01 plane β -Ga 2 O 3 bulk substrate. The minimum thickness of 57.3 nm was obtained for the very thin (100) plane β -Ga 2 O 3 channel layer of the FET using inductively coupled plasma etching with BCl 3 /N 2 chemistry. The current-voltage characteristics of the FET with various β -Ga 2 O 3 channel thickness was investigated. The dependence of the channel thickness on the drain current density, threshold voltage, transconductance, and field effect mobility was studied. The hydrogen response of the (100) plane Ga 2 O 3 flake based FET with catalytic Pt gate surface was measured in the range of 10–500 ppm at 400 °C, and modeled with a dissoci…