AlGaN/GaN Schottky-Gate HEMTs With UV/O₃-Treated Gate Interface

Ti3C2Tx MXene van der Waals Gate Contact for GaN High Electron Mobility Transistors

“…The I ON / I OFF ratios are comparable to those in previous reports obtained using Ni/Au as the contact in the D‐mode Schottky gate GaN HEMTs. [ 4,9,28,57 ] On the other hand, the I Gmax can be suppressed to lower values from ≈10 −6 to ≈10 −7 (mA mm −1 ) with the MXene‐gate GaN HEMTs. The I ON / I OFF ratios ranging from 2.1 × 10 8 to 3.3 × 10 9 are two to three orders of improvement compared with the Ni/Au‐gate GaN HEMTs.…”

“…The I ON /I OFF ratios are comparable to those in previous reports obtained using Ni/Au as the contact in the D-mode Schottky gate GaN HEMTs. [4,9,28,57] On the other hand, the I Gmax can be suppressed to lower values from The statistical analysis of measured µ FE was performed and shown in Figure 3k, and the calculation procedure is shown in Figure S6 (Supporting Information). Compared with the Ni/Au-gate GaN HEMTs, the MXene-gate GaN HEMTs exhibit ≈1.5 times higher µ FE .…”

“…As a result, a higher Schottky barrier height was obtained, as verified by the ultraviolet photoelectron spectroscopy (UPS) measurement (Supporting Information Figures S12 and S13 Figure 5c, the I OFF of GaN HEMTs can be significantly reduced for the O-MXene contact, and accordingly, the I ON /I OFF ratio can be increased by four orders of magnitude to ≈10 13 , which is six orders higher than that for the traditional Ni/Au-gate GaN HEMTs. [28,57] In addition, the ML-, FL-, and O-MXene-gate GaN HEMTs exhibit no noticeable difference in the maximum I D based on the output current density curves (Figure S15, Supporting Information). Figure 5h compares the performance of GaN HEMTs with MXenes and other materials as gate electrodes.…”

Positive Shifting of Vth with Enhanced DC Performance in AlGaN/GaN Schottky-Gate HEMT through Optimized UV/O3 Treated Gate Interface and Thermal Engineering

“…5 In addition to the high voltage, high speed, and low on resistance characteristics of the AlGaN/GaN HEMTs, the high gate leakage current (I G ) affects noise, reliability and radio-frequency power loss of the device. 6 Thus, the gate leakage current should be carefully examined. The high gate leakage current due to the strong polarization-induced electric field and Schottky gate contact limits the performance of the AlGaN/GaN HEMTs.…”

“…8 The gate leakage current is highly dependent on the surface condition and surface treatment methods used to reduce the interface trap densities rather than the intrinsic parameters. 6 Previous reports also mention that the carrier charging/discharging at a large amount of traps could results in degradation in conduction current, dynamic on-resistance, current collapse, switching loss and induce trap assisted tunneling etc during device operation. [9][10][11][12][13] Moreover, observations also confirm that due to the presence of lots of surface states at source/drain (S/D) access region, the HEMTs suffer from severe current collapse.…”