arXiv subjects

Noor Jahan Nipu

Publications and source records attributed to Noor Jahan Nipu.

3 recordsLinked to original sources

arXiv2026

Sub-Micron Gate $β-Ga_{2}O_{3}$ FinFETs with Current Density $>$ 750 mA/mm and Ion/Ioff Ratio $>$ $10^{9}$

In this work, we demonstrate submicron-gate $β-Ga_{2}O_{3}$ FinFETs that integrate Si delta-doped channels with selectively regrown n++ source/drain contacts. The devices employ 100 nm-wide fins to improve electrostatic control of a high sheet charge density channel of $3.3\times 10^{13}$ cm-2. A 150 nm-gate-length FinFET exhibits a maximum drain current density of 764 mA/mm at VGS = 1 V and VDS = 10 V, an on-resistance of 9.1 $Ω$.mm, and an Ion/Ioff ratio exceeding $10^9$. The device also shows a peak transconductance of 43 mS/mm and de-embedded $f_{T}/f_{MAX}$ values of 6.3/2.0 GHz. Pulsed I-V measurements indicate ~20 % current collapse, attributed primarily to trapping at etched fin sidewalls and the $Al_{2} O_{3}$/ $β-Ga_{2}O_{3}$ interface. These results show that delta-doped $β-Ga_{2}O_{3}$ FinFETs can simultaneously achieve high drive current, strong current modulation, and GHz-frequency operation, providing a scalable device platform for future power and RF electronics.

physics.app-ph↗

arXiv2026

Beta-AlGaO/Ga2O3 Tri-Gate MOSHEMT with 70GHz fT and 55GHz fmax

We report Beta-AlGaO/Ga2O3 tri-gate heterostructure MOSHEMTs incorporating a thin 5 nm Al2O3 gate oxide layer for improved gate control and reduced leakage. The devices were fabricated on AlGaO/GaO heterostructures grown by ozone MBE on Fe-doped Ga2O3 (010) substrates. The tri-gate MOSHEMTs, with 1 micron-wide fins and Lg=155 nm, exhibit a peak current-gain cut-off frequency fT=70 GHz and a power-gain cut-off frequency fMAX=55 GHz.The fT.L product of 10.85 GHz-micron is the highest among reported Ga2O3 FETs to date. The devices show Vth =-0.5 V, an on/off ratio 10^6 I=80 mA/mm, a peak gm=60 mS/mm, and a low gate leakage current of 10^(-10) mA/mm at Vgs=0.5 V. Passivation with a 100 nm ALD Al2O3 layer effectively removes DC/RF dispersion and maintains stable operation under pulsed IV and repeated RF measurements. These results demonstrate the potential of tri-gate AlGaO/GaO MOSHEMTs for next-generation high-frequency and high-power applications.

cond-mat.mtrl-sci↗

arXiv2025

High performance vacuum annealed beta-(AlxGa1-x)2O3/Ga2O3 HFET with f_T/f_MAX of 32/65 GHz

This letter reports high performance beta-(AlxGa1-x)2O3/Ga2O3 Heterostructure FET (HFET) with improved regrowth process. Highly scaled I shaped gate have been fabricated with degenerately doped (N++) source/drain contact regrown by ozone molecular beam epitaxy (MBE). Aiming to address the limitations observed in previous generation devices, this work incorporates a low-power BCl3/Ar and SF6/Ar plasma etching process to remove the AlGaO barrier layer and Ga2O3 layer respectively before regrowth. Additionally, the surface was cleaned and vacuum annealing was carried out before MBE regrowth to reduce any interface resistance between highly doped regrowth N++ and 2DEG layer. These meticulously designed fabrication steps enabled us to achieve the high DC current 0.5 A/mm at 5V drain bias with 6.1 $\mathrmΩ$.mm on resistance (R\textsubscript{ON}) at V_GS=3V, peak transconductance (g_m) of 110 mS/mm at room temperature (V_DS=15V) and around 0.8 A/mm (V_DS=5V) peak I_ON} at low temperature (100K). Current gain cut-off frequency (f_T) of 32 GHz and peak power gain cut-off frequency (f_MAX) of 65 GHz were extracted from RF measurements. f_T.L_G product was estimated to be 6.1 GHz-$μ$m for 191 nm L_G and 32 GHz f_T, which is one of the highest reported among Ga2O3 devices. With thicker Al2O3, device shows no current collapse demonstrating first time successful traps passivation with Al2O3 for Ga2O3 devices.

cond-mat.mtrl-sci↗