Performance Improvement of Enhanced-Mode β-Ga<sub>2</sub>O<sub>3</sub> MOSFETs by Partial Gate Recess Structure
Yueh-Han Chuang, Fu‐Gow Tarntair, Pei-Jung Wang, Tian‐Li Wu, Niall Tumilty, Ray‐Hua Horng
Abstract
In this study, β-Ga 2 O 3 films were grown on the c-plane sapphire substrate by metal–organic chemical vapor deposition. Gate-recessed heteroepitaxial β-Ga 2 O 3 metal oxide semiconductor field effect transistors (MOSFETs) were fabricated to achieve enhanced mode operation. It was found that the conductivity of Ga 2 O 3 films can be further improved by in situ doping and a partial gate recess. Output current increased from 4.21 to 5.76 mA/mm, R on.sp decreased from 392 mΩ.cm 2 to 238 mΩ.cm 2,and μ FE increased from 15 cm 2 /(V s) to 19.9 cm 2 /(V s) for MOSFETs with partial gate recesses of 7 and 5 μm, respectively. Device threshold voltages are positive, possessing low R on and impressive I D on/off ratios. Breakdown voltage was increased using a gate field plate. In summary, device performance was improved using shorter gate recesses for enhanced mode β-Ga 2 O 3 MOSFETs.