Enhancement‐Mode β‐Ga₂O₃ Metal‐Oxide‐Semiconductor Field‐Effect Transistor with High Breakdown Voltage over 3000 V Realized by Oxygen Annealing

Abstract

Herein, high‐performance enhancement‐mode (E‐mode) β‐Ga2O3 metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) are achieved on Si‐doped homoepitaxial films. Oxygen annealing (OA) treatment under the gate region is used to effectively exhaust the channel electron, resulting in the normally off operation of the device. The threshold voltage, defined as that at the drain current of 0.1 mA mm−1, for the fabricated device is extracted to be 4.1 V. Moreover, double source‐connected field plates are used to suppress the peak electric fields in both Ga2O3 channel and SiNx passivation layer. The fabricated β‐Ga2O3 MOSFETs with gate‐to‐drain distance (Lgd) of 17 μm exhibit a record high breakdown voltage over 3000 V. It is shown that the OA treatment is a new way to obtain high‐performance E‐mode β‐Ga2O3 power MOSFETs.

Low field transport calculation of 2-dimensional electron gas in β-(AlxGa1−x)2O3/Ga2O3 heterostructures

“…There are several experimental measurements on modulation doped transistor of AlGa 2 O 3 /Ga 2 O 3 reporting low field electronic mobility at low and room temperature [26][27][28][29][30][31] . Zhang et al 27 recently reported velocity-field characteristics of such heterostructures at 50 K and the corresponding low field mobility and saturation velocity are found to be ∼ 1500 cm 2 V −1 s −1 and 1.1×10 7 cms −1 respectively. The high field electron transport in a bulk material has been reported previously 32 .…”

“…β −Ga 2 O 3 is a promising wide-bandgap semiconductor material known for its potential applications in high voltage power electronics [1][2][3][4][5][6][7][8][9][10] and high power radio frequency (RF) switching [11][12][13][14] . The power electronics application comes from its large Baligas's figure of merit (BFoM = ε µE 3 c ) resulting from its wide bandgap (4.8 eV) [15][16][17][18] and a very high estimated breakdown field (E c = 8 MVcm −1 ) 19 .…”

State-of-the-Art β-Ga2O3 Field-Effect Transistors for Power Electronics

“…The β-Ga 2 O 3 MOSFET can achieve maximum g m of 44 mS mm −1 at V GS = 2 V and V DS = 12 V, and record high f T = 27 GHz and f MAX = 16 GHz. 108 In order to further improve the large-signal RF performance, it is critical to avoid current collapse at high MOSFET with a narrow UID channel, 113 (C) MOSFET with an oxygen annealed channel and double source-connected field-plates, 114 (D) MOSFET with a recessed gate, 115 (E) bottom-gate MOSFET with an 8-nm-thin channel, 116 (F) MISFET with a vertical fin channel, 117 (G) MOSFET with a vertical current aperture, 118 and (H) MOSFET with a N-doped channel.…”

“…The β-Ga 2 O 3 MOSFET with the double source-connected field-plates and L GD = 17 μm can achieve record high V br > 3000 V in Fluorinert FC-770, R on,sp = 163 mΩ cm 2 , and PFOM > 55.2 MW cm −2 (Table 5C). 114 Recessed Gates or Ultrathin Channels. As described previously, small-sized and recessed gates are useful in rapidly controlling the channels for RF operations.…”

Ion implantation in β-Ga2O3: Physics and technology

“…126 , the values of V br = 2900 V and BFOM = 182 MW×cm -2 were obtained for devices of this type (at the distance between the gate and drain L GD = 17.8 μm) using a T-shaped gate and Al 2 O 3 /HfO 2 layers as a gate dielectric. For the E-mode FP-MOSFET 127 , the use of Si + implantation for the source and drain formation made it possible to achieve the following values of V br , BFOM, and contact resistance R c : 3000 V; 94 MW×cm -2 ; 2 Ω ×mm, respectively. Finally, in Ref.…”