Influence of gate recess on the electronic characteristics of β-Ga2O3 MOSFETs

Review of gallium oxide based field-effect transistors and Schottky barrier diodes

“…A recessed type gate of this kind occupied partial channel layer and fully depleted the channel under the 1-µm gate region even at V GS = 0 V (normally-off E-mode). Lv et al [67] studied the effects of recessed gate on FET performances in a Si-doped β -Ga 2 O 3 MOSFET with 25 nm HfO 2 as the gate dielectric. The saturation drain current declined from 20.7 mA/mm to 2.6 mA/mm when the recess depths increased from 110 nm to 220 nm, while the threshold voltage shifted from −4.9 V to 3 V. Such preferable performances were mainly due to the contributions of the recessed gate by suppressing the electric field close to the gate side.…”

Gate-mesa trench enables enhanced β-Ga2O3 MOSFET with higher power figure of merit

“…However, for practical power applications, enhancement-mode β-Ga 2 O 3 is preferred as it reduces off-state power consumption and enables safe operation at higher voltages. However, the absence of p-type doping technology of β-Ga 2 O 3 is detrimental to the implementation of power switching devices [4,12]. To achieve enhancement-mode β-Ga 2 O 3 MOSFETs, various device structures and process optimizations, such as variation of lateral doping (VLD) [13], vertical structure [14], and p-NiO/n-Ga 2 O 3 heterojunction [15,16], have been explored.…”

Enhancement Mode Ga2O3 Field Effect Transistor with Local Thinning Channel Layer

“…However, an n−type Ga 2 O 3 FET is a depletion−mode device with a negative threshold voltage (V th ); with the lack of effective p−type doping, enhancement−mode (e−mode) operation has been limited. Enhancement−mode devices are preferred to mitigate the off−state power dissipation and for safe high−voltage operations in practical power applications [27].…”

“…Chabak et al [28] fabricated Sn−doped Ga 2 O 3 wrap−gate fin−array field−effect transistors (finFETs) with a threshold voltage between 0 and +1 V. Zongyang Hu et al [29] fabricated an enhancement−mode Ga 2 O 3 vertical power metal-insulator field−effect transistors with fin−shaped channels. Yuanjie Lv et al [27] fabricated Ga 2 O 3 metal−oxide−semiconductor field−effect transistors with gate recess depths of 110 nm and 220 nm, respectively. Additionally, upon increasing the recess depth, the threshold voltage increased to +3 V. Kamimura et al [30] fabricated enhancement−mode devices using N−Si co−doping technology.…”