Contact engineering of GaN-on-silicon power devices for breakdown voltage enhancement

Abstract

Two contact engineering approaches are proposed and investigated to enhance the breakdown voltage V BK in GaN-on-Si power devices, including the hybrid Schottky-ohmic-drain structure for AlGaN/GaN HEMTs and the selective Si-diffusion structure for AlGaN/GaN SBDs. With the hybrid Schottky-ohmic drain, the devices showed a zero onset voltage and reduced off-state leakage current by one order of magnitude, compared with that of the traditional ohmic-drain devices. The breakdown voltage was also enhanced with comparable on-resistance. For the SBDs with the selective silicon-diffusion layer underneath ohmic metal at the cathode, a low-contact resistance R c of 0.2 mm and a smooth ohmic metal morphology were obtained. The SBDs with the additional silicon diffusion layer showed enhanced V BK , compared with that of the conventional SBDs. The results demonstrate that the proposed contact engineering approaches are useful for the breakdown voltage enhancement of GaN-on-Si power devices.

AlGaN/GaN High Electron Mobility Transistors with Multi‐MgxNy/GaN Buffer

“…In other words, the transistor corresponding to sample A could not be turned off completely, even with a large negative gate bias applied. It has been reported that nonisolated channel or poor Schottky gate contact could result in a large S-D leakage current in HEMT devices [5]. However, since the same processing condition was implemented on both samples, we believe that the large S-D leakage current was originated instead from the 2.2 m thick unintentionally doped GaN layer.…”

Low On‐Resistance and Low Trapping Effects in 1200 V Superlattice GaN‐on‐Silicon Heterostructures

“…At the time of global warming, Gallium nitride on silicon (GaN-on-Si) technologies are highly promising to solve energy issues in the future [1][2]. Although the growth of GaN-on-Si represents a real challenge in managing large lattice and thermal mismatch [3][4][5][6], this technology remains the best candidate owing to its superior intrinsic properties such as high breakdown voltage (BV), large band-gap, high electron saturation velocity, low on-resistance, suitable for high volume commercialization of low cost substrates [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”

Effect of N2O/BCl3Cyclical Recess Etching Technique Used Prior to Anode Metal Deposition in AlGaN/GaN Schottky Barrier Diodes

“…4,5 Additionally, GaN-based Schottky barrier diodes (SBDs) are being preferentially developed as unipolar devices, and could offer high switching speeds and low reverse recovery loss as well as maintain a high blocking voltage. [6][7][8] GaN-based SBDs require a low turn-on voltage (V ON ) and specific on resistance (R ON,SP ) coupled with reverse gate leakage reduction for a high reverse breakdown voltage (V BR ) to minimize power loss during operation.…”