Electrical and Electronic Engineering, Materials Science
37
Scopus Publications
Scopus Publications
Performance Study of Sub-5 nm FinFET and GAA Structures at Low Temperature Bhubesh Chander Joshi, Ajeet Kumar Semiconductors, 2025 Abstract This work investigates the cryogenic performance of 5 nm FinFET and Gate-All-Around (GAA) transistors, focusing on their electrical, thermal, and noise properties. Both devices exhibit better transconductance (gm), threshold voltage (Vth), drain current (IDS), subthreshold swing (SS), leakage current, on/off ratio, and noise figure (F) at low temperatures. FinFETs show maximum transconductance of 79.3 µS, an SS of about 20 mV/dec, and an on/off current ratio of about 1035 at low temperature. They can drive currents of up to 341 µA at 20 K. GAA transistors, on the other hand, have better electrostatic control, with a higher Vth (0.73 V vs. 0.65 V for FinFET), a sharper SS of around 10 mV/dec, and a better on/off current ratio of about 1049. Thermal study indicates that FinFETs exhibit higher self-heating (~91 K) than GAA (~80.5 K), with heat concentrated near the drain end of the channel in FinFETs and near the source end of the channel in GAA transistors. Noise study shows that both thermal and generation–recombination noises are lower at cryogenic temperatures. Multi-gate wrapping can further reduce these noises. Overall, at cryogenic temperatures, the 5 nm FinFET architecture is more suitable for high-current electronics, whereas GAA transistors are more favourable for low-noise and low-power electronics, demonstrating their potential applications in quantum computers and other cryogenic technologies.
AlGaN/GaN heterostructures for high power and high-speed applications Bhubesh Chander Joshi International Journal of Materials Research, 2023 AlGaN/GaN heterostructures are one of the most promising semiconducting structures for fabricating high-speed and high-power electronic devices such as high electron mobility transistors and heterojunction bipolar transistors. Due to the lack of native substrates, these epitaxial structures are generally grown on foreign substrate materials such as sapphire, SiC and Si by using two-step growth techniques. In this paper, a few test structures along with TLM pads, FET structure, ohmic contacts and Schottky contacts have been fabricated on AlGaN/GaN heterostructure by photolithography, reactive ion etching, and e-beam metallization. Transmission line measurement has been used to calculate the sheet resistivity and contact resistance of ohmic pads. Current voltage measurement is used to test an FET structure of size 1 × 150 µm2 with a gate length of 4 µm and source to drain spacing of 5 µm.
Improvement in internal quantum efficiency of InGaN/GaN light emitting diodes by linear grading of quantum wells Optoelectronics and Advanced Materials Rapid Communications, 2016
High Al composition and enhancement mode AlGaN/GaN HEMT for microwave applications International Journal of Microwave and Optical Technology, 2011
New techniques to extract heat from GaN based high electron mobility transistors and LEDs Optoelectronics and Advanced Materials Rapid Communications, 2010
