Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length
Journal
Nanoscale Research Letters
Journal Volume
12
Pages
156-168
Date Issued
2017
Author(s)
Chien, CY (Chien, Cheng-Yen)
Wu, WH (Wu, Wen-Hsin)
You, YH (You, Yao-Hong)
Lin, JH (Lin, Jun-Huei)
Lee, CY (Lee, Chia-Yu)
Hsu, WC (Hsu, Wen-Ching)
Kuan, CH (Kuan, Chieh-Hsiung)
Lin, RM (Lin, Ray-Ming)
CHIEH-HSIUNG KUAN
Abstract
We present new normally off GaN high-electron-mobility transistors (HEMTs) that overcome the typical limitations in multi-mesa-channel (MMC) width through modulation of the via-hole-length to regulate the charge neutrality screen effect. We have prepared enhancement-mode (E-mode) GaN HEMTs having widths of up to 300 nm, based on an enhanced surface pinning effect. E-mode GaN HEMTs having MMC structures and widths as well as via-hole-lengths of 100 nm/2 μm and 300 nm/6 μm, respectively, exhibited positive threshold voltages (Vth) of 0.79 and 0.46 V, respectively. The on-resistances of the MMC and via-hole-length structures were lower than those of typical tri-gate nanoribbon GaN HEMTs. In addition, the devices not only achieved the E-mode but also improved the power performance of the GaN HEMTs and effectively mitigated the device thermal effect. We controlled the via-hole-length sidewall surface pinning effect to obtain the E-mode GaN HEMTs. Our findings suggest that via-hole-length normally off GaN HEMTs have great potential for use in next-generation power electronics.
SDGs
Type
journal article