# Arathy VargheseCardiff University | CU · School of Engineering

Doctor of Philosophy

30
Publications
4,915
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175
Citations
Citations since 2016
28 Research Items
173 Citations
November 2020 - present
Position
• Research Associate
January 2020 - October 2020
Position
• PostDoc Position
July 2018 - August 2018
Position
• INUP user

## Publications

Publications (30)
Article
Resolution of HEMT sensors needs to be improved to make feasible the precise detection of antigens from body fluids like saliva instead of blood. For enhancing sensitivity and long-term stability, a systematical study of the device becomes mandatory which is impossible without the aid of an analytical model. Presented through this work is a mathema...
Article
Sensitivity enhancement of undoped AlGaN/AlN/GaN HEMT for pH detection through the use of dielectric $\rm (10nm Al_{2}O_{3})$ based MOS gated structure has been demonstrated through this letter. Linear and Circular MOS-HEMT (L-MOSHEMT and C-MOSHEMT) with similar dimensions have been fabricated on Si substrate. Novel sensing metric \$\rm g_{d}/I_{...
Article
This paper presents the applicability of a high-resolution AlGaN/AlN/GaN metal oxide semiconductor-high electron mobility transistor (MOS-HEMT) for multiple bio detection and analysis of its sensitivity through a charge deduction based approach. The biomarkers of interest chosen in this paper include c-erbB-2, the breast cancer biomarker whose dete...
Article
This work reports the fabrication, characterization and testing for pH sensitivity of dielectric modulated MOS-HEMT(Metal oxide semiconductorhigh electron mobility transistor) devices for bio-sensing applications. The primary aim here is to develop high sensing devices for bio-detections. The oxide based gate area is used in ensuring the device per...
Article
C-MOSHEMT (Circular-Metal Oxide Semiconductor High Electron Mobility Transistor) has been modeled, fabricated and sensitivity analysis has been done for pH detection application for the first time. Prototype model of the sensor has been developed considering a ring gate structure. The perimeter of the gate inner ring is taken as the gate length and...
Article
Full-text available
This paper presents a comprehensive literature survey of MEMS based piezoelectric microphones along with the fabrication processes involved, application domains, and methodologies used for experimentations. Advantages and limitations of existing microphones are presented with the impact of process parameters during the thin film growth. This review...
Article
This work presents performance evaluation of GaN High Electron Mobility Transistor (HEMT) based ultraviolet (UV) detector on Si substrate. In addition to the fabrication and characterization, a systematic study is presented here using simulations extensively to investigate the UV detection mechanism. Output current has been chosen as the sensing me...
Article
Full-text available
This work presents the performance evaluation of Graphene/ZnO Schottky junctions grown on flexible indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates. The fabricated structures include chemical vapour deposition grown graphene layer on ITO-coated PET substrates. Polymethyl methacrylate assisted transfer method has been employ...
Article
Full-text available
This research article reports the operational characteristics of gate field plate double heterojunction (DH) high electron mobility transistors (HEMTs) using SiN (SiO2) passivation techniques. The proposed HEMT exhibits 496 (292) V breakdown voltage (VBR) for LG (gate-length) = 0.25 μm, LGD (drain-gate distance) = 3.2 μm and 1 μm field plate length...
Article
Sensing COVID-19, GOx (glucose oxidase enzyme) in exhaled breath condensate/saliva, bio-molecules like KIM (Kidney Injury Molecule) in human body and pH value in human body fluids have gained huge attention in the present scenario as well as in the past decade. Hence, for the first time, double channel technique in AlGaN/GaN High Electron Mobility...
Article
This work describes the self-heating effects on the behavior of AlGaN/GaN-based high-electron Mobility Transistors (HEMTs), which are grownon Sapphire substrate, using electro-thermal TCAD simulations. The proposed device, passivated with AlN/SiN, demonstrates more excellent thermal performance than the conventional one with SiN passivation due to...
Article
The paper reports development of graphene/ZnO heterojunction Schottky diode structure and its structural and electrical characterization. Graphene is grown on copper substrate using chemical vapor deposition (CVD) and transferred on flexible substrate (indium Tin Oxide coated PET). The grown thin layer is characterized using scanning electron micro...
Article
Unlike other FETs where a sub-threshold regime is preferred for pH detection where power is a constraint, here both subthreshold and saturation region of operation can be used for sensing. In the sat- uration region, a large change in drain current shift is obtained compared to the sub-threshold region which leads to enhanced sensitivity. Similarly...
Article
Presented through this work is a steady state analytical model of the GaN HEMT based gas detector. GaN with high chemical and thermal stability provides promises for detectors in hazardous environments. However, HEMT sensor resolution must be improved to develop high precision gas sensors for automotive and space applications. The proposed model ai...
Article
This letter presents analytical and TCAD models for analyzing the performance of bio-HEMT (High Electron Mobility Transistor) sensors. Unlike existing models for these sensors in literature, where the bio-layer is modeled as semiconductor or insulator layer with analyte-induced interface charge (i.e. surface potential), the model presented in this...
Article
In this work, GaN/AlN/AlGaN MOS-HEMT with a cavity below the gate towards the drain side is studied for its sensitivity analysis and viability as a biosensor. The analysis is done by dielectric modulation of the cavity region to emulate the presence of different dielectric biomolecules and charged biomolecules by interface charge variation. MOSFET-...
Article
Full-text available
This article presents the investigations done for performance enhancement evaluation of n+ doped graded InGaN drain/source region-based HfO2/InAlN/AlN/GaN/AlN on SiC metal-oxide-semiconductor high electron mobility transistor (MOS-HEMTs) with T gate. Impact on device characteristics with the inclusion of the HfO2 surface passivation layer and AlN b...
Article
Full-text available
The performance of AlGaN/GaN HEMT is enhanced by using discrete field plate (DFP) and AlGaN blocking layer. The AlGaN blocking layer provides an excellent confinement of electrons toward the GaN channel, resulting very low subthreshold drain current of 10−8 A/mm. It reveals very high off state breakdown voltage (BV) of 342 V for 250 nm gate technol...
Conference Paper
EMG signal is widely accepted in human-machine interaction applications, such as prosthesis control and rehabilitation devices. The existing feature extraction methods struggle to separate a variety of EMG based activities. In the proposed work, a novel feature defined as PAP (peak average power) has been proposed. This feature has been validated f...
Article
Developing and optimizing FET platforms for label free bio molecule detection has gained huge interest in recent years. This paper presents a charge control model based sensitivity analysis of an optimized GaN HEMT for pH and biomarker detection. Analytical modeling, simulation and fabrication of the device have been discussed in this paper with fo...
Article
An alternative to conventional field effect transistors Tunnel Field Effect Transistor (TFET) provides a very steep sub threshold slope and low leakage current. Doping less Silicon TFET avoids certain challenges faced by TFET like effects of Random Dopant Fluctuations (RDF), like an unacceptably large increase in the OFF-state current and need of h...
Conference Paper
Full-text available
In order to improve the energy efficiency of next generation digital systems, transistors with Subthreshold Slope < 45 mV/decade of drain current are needed. Tunnel Field Effect Transistor (TFET) s are attractive new devices for low power applications by its virtues of reduced short channel effects, low off current and their potential for a small s...
Conference Paper
Full-text available

## Questions

Questions (3)
Question
How can I define a quartenary compound such as InxAlyGa(1-x-y)N in Silvaco?
Question
If yes what is the concentration of acid required?
Question
I wish to grow GaN HEMT on SiC substrate with different barrier materials, where can I find facilities for the same through MOCVD/MBE (preferably in India).

Cited By

## Projects

Projects (4)
Project
Design and Fabrication of a low cost, highly sensitive junctionless BioFET architecture.
Project
Prototype the model for non invasive blood glucose measurement
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