Quasi-vertical GaN-on-Si reverse blocking power MOSFETs

Abstract

We demonstrate quasi-vertical reverse blocking (RB) MOSFETs on 6.7 μm thick GaN grown on a 6 inch Si substrate by metalorganic chemical vapor deposition. The RB capability was achieved by replacing the ohmic drain with a quasi-vertical Schottky drain, resulting in a RB voltage of ∼300 V while preserving the ON-resistance (R on,sp). Schottky contacts on etched i-GaN surface were realized through an optimized fabrication process based on tetramethylammonium hydroxide treatments. The fabricated RB-MOSFET had a low R on,sp of 4.75 mΩ cm2, current density of ∼0.9 kA cm−2 and a forward blocking voltage of 570 V.

Accurate Band Offset Prediction of Sc2O3/GaN and θ-Al2O3/GaN Heterojunctions Using a Dielectric-Dependent Hybrid Functional

“…Wide-bandgap semiconductors, such as GaN, are of great interest in condensed matter physics and microelectronics applications . Gallium nitride has an ultrawide bandgap of about 3.4 eV, which has the advantages of high power, high electron mobility, high electron saturation velocity, and high breakdown electric field, so it has been widely studied and applied in various transistors. − GaN-based electronic devices are mainly composed of lateral heterojunctions grown on large and low-cost substrates. With the development of the epitaxy technique, device design, machining technology, and gate drive technology, the commercialized GaN-based heterojunction devices grown on silicon substrates have achieved impressive power conversion efficiency as well as a compact size .…”

GaN quasi-vertical trench MOSFETs grown on Si substrate with ON-current exceeding 1 A

“…Recently, quasi-and fully-vertical GaN trench MOSFETs with large V th have been reported on Si substrates. [14][15][16][17] The reported GaN-on-Si trench MOSFETs showed relevantly high specific ON-resistance (R ON,sp > 4 mΩ•cm 2 ). [14][15][16][17] In addition, the demonstrated devices employing single-trench design provided a limited maximum ON-current (<10 mA).…”

“…[14][15][16][17] The reported GaN-on-Si trench MOSFETs showed relevantly high specific ON-resistance (R ON,sp > 4 mΩ•cm 2 ). [14][15][16][17] In addition, the demonstrated devices employing single-trench design provided a limited maximum ON-current (<10 mA). [14][15][16][17] In this letter, we report GaN-based quasi-vertical trench gate MOSFETs on cost-effective Si substrate with ONcurrent exceeding 1 A.…”

“…1) Because of the vertical topology, a higher V BR can be effectuated by introducing a thicker drift layer without increasing the device area. 1) In the past decade, high-performance GaN vertical transistors, including current aperture vertical electron transistors, [2][3][4][5][6][7] fin power FETs, [8][9][10] and trench MOSFETs [11][12][13][14][15][16][17][18][19] have been demonstrated. Compared with other types of vertical transistors, GaN trench MOSFETs have the advantages of a simpler fabrication process and larger V th .…”

“…[14][15][16][17] In addition, the demonstrated devices employing single-trench design provided a limited maximum ON-current (<10 mA). [14][15][16][17] In this letter, we report GaN-based quasi-vertical trench gate MOSFETs on cost-effective Si substrate with ONcurrent exceeding 1 A. The best device with single-trench design shows a low R ON,sp of 0.84 mΩ•cm 2 , a high maximum drain current density (I D,max ) of 5.0 kA cm −2 , a high V th of 5.3 V (at I D = 1 A cm −2 ) and a V BR of 320 V, after finetuning of the channel doping and adoption of a thick bottom dielectric process.…”