Fabrication of Normally Off AlGaN/GaN MOSFET Using a Self-Terminating Gate Recess Etching Technique

Enhancement Mode (E-Mode) AlGaN/GaN MOSFET With $10^{-13}$ A/mm Leakage Current and $10^{12}$ ON/OFF Current Ratio

“…window was oxidized for 60min at 615°C followed by 60min etching in KOH solution at 70°C. The recess process was selfterminated at the AlGaN/GaN interface [7]. The recess region was characterized by atomic force microscope (AFM) after removal of SiO 2 by BOE.…”

“…However, very few investigations have been reported on this issue for E-mode AlGaN/GaN devices although they are preferred in high temperature digital [4] and [6] which deserves to be studied. In this letter, E-mode AlGaN/GaN MOSFET is fabricated based on our proposed self-terminating gate recess etching technique [7]. Post gate annealing (PGA) in N 2 /O 2 atmosphere at 300°C is employed on it to reduce mesa isolation current (I mesa ) which, as a result, leads to an enhancement of the off state leakage current (I off ) and on/off current ratio (I on /I off ) for the device.…”

Effective Channel Mobility of AlGaN/GaN-on-Si Recessed-MOS-HFETs

“…In this case, the channel mobility will be significantly decreased due to the absence of 2DEG channel and strong scattering effects with interface charges existing at the recessed MIS channel itself. While great efforts have been made to improve the channel mobility of AlGaN/GaN recessed-MIS devices [7,11,12], careful investigation on mobility characteristics have not been reported yet. In this work, we have investigated the channel mobility characteristics of normally-off AlGaN/GaN-on-Si recessed-MOSHFETs with SiO 2 gate oxide.…”

Formation of combined partially recessed and multiple fluorinated-dielectric layers gate structures for high threshold voltage GaN-based HEMT power devices

“…To simplify circuit design and provide a better fail-safe operation in the power switching applications, a normally-off mode with a large threshold voltage (V th > 3 V) is required. Recently, various approaches such as gate recess etching [11][12][13][14][15], fluorinated gate or gate dielectric [16][17][18][19][20][21][22][23][24], and p-gate cap layer [25][26][27] have been explored to realize the normally-off operation. However, there are still several shortcomings in these devices.…”