Design and fabrication of field-plated normally off β -Ga2O3 MOSFET with laminated-ferroelectric charge storage gate for high power application

Abstract

In this work, an enhancement-mode (E-mode) β-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) has been achieved by incorporating a laminated-ferroelectric charge storage gate (L-FeG) structure [Al2O3/HfO2/Al2O3/Hf0.5Zr0.5O2 (HZO) of 10/5/2/16 nm]. The band diagram between L-FeG dielectrics (Al2O3, HfO2, and HZO) and β-Ga2O3 was determined by x-ray photoelectron spectroscopy. After applying a gate pulse with an intensity of +18 V and width of 1 ms, the saturation current of the E-mode device was measured to be 23.2 mA/mm, which shows a negligible current reduction compared to that of 22.1 mA/mm in a depletion- (D-) mode device. In addition, the threshold voltage (VTH) is only shifted by 2.76% and 2.18%, respectively, after applying the gate stress and gate-drain stress of 15 V for 104 s. Meanwhile, a high breakdown voltage of 2142 V and specific on-resistance (RON,sp) of 23.84 mΩ·cm2 were also achieved, which correspond to a state-of-art high power figure of merit of 192.5 MW/cm2, showing the great potential of combing the ferroelectric gate stack and lateral Ga2O3 MOSFET as next generation power devices.

Ferroelectric α‐In2Se3 Wrapped‐Gate β‐Ga2O3 Field‐Effect Transistors for Dynamic Threshold Voltage Control

“…The interface trapped charge density ( Q IL ) causes carrier depletion in the channel and increases a memory window. [ 14,16 ] Figure 4d shows charge density profiles based on the charge density simulation. The amount of Q fe from the α‐In 2 Se 3 FET is calculated to be ≈0.37 µC cm −2 at a V C of 5.5 V. However, the amount of Q fe from the β‐Ga 2 O 3 /α‐In 2 Se 3 FET is calculated to be ≈0.24 µC cm −2 from the amount of V TH shift in Figure 3c.…”

“…Hence, various approaches have been actively investigated, including channel geometry and thickness modification, [ 7–9 ] ion‐implanted Si doping, [ 10 ] high‐k dielectrics, [ 11–13 ] as well as ferroelectric hafnium zirconium oxide layers. [ 14–16 ]…”

T-Gate shaped AlN/β-Ga2O3 HEMT for RF and High Power Nanoelectronics

“…of 11 and 192.5 MW/cm 2 are reported in [10], and [17] respectively. However, these devices have used relatively thick epi-channel of 200 nm and large gate length of > 1µm together make them less relevant for RF applications.…”

“…The β-Ga2O3 device technology has a footprint in almost all power devices including Schottky barrier diodes [5], [6], MESFETs [7], [8], MOSFETs: depletion-mode (D-mode) [9]- [12] and enhancement-mode (E-mode) [13]- [17], and HEMTs [18], [19]. Specifically, a high breakdown field of 3.8 and 5.2 MV/cm is reported in β-Ga2O3 lateral MOSFET [10] and β-Ga2O3 vertical heterostructure [20].…”

T-Gate shaped AlN/β-Ga2O3 HEMT for RF and High Power Nanoelectronics

“…The β-Ga2O3 device technology has a footprint in almost all power devices including Schottky barrier diodes [5], [6], MESFETs [7], [8], MOSFETs: depletion-mode (D-mode) [9]- [12] and enhancement-mode (E-mode) [13]- [17], and HEMTs [18], [19]. Specifically, a high breakdown field of 3.8 and 5.2 MV/cm is reported in β-Ga2O3 lateral MOSFET [10] and β-Ga2O3 vertical heterostructure [20].…”