Raj Kumar.J.S.

@karunya.edu

Assistant Professor in the Department of Computer Science and Engineering
Karunya Institute of Technology and Sciences



                 

https://researchid.co/rajkumar.j.s.

RESEARCH INTERESTS

Device Modelling
High power VLSI Design
HEMT
Nano electronics

15

Scopus Publications

81

Scholar Citations

4

Scholar h-index

2

Scholar i10-index

Scopus Publications

  • Monitoring Industrial Protection Gear Using Intelligent System
    Yakubraj M, Rajkumar J S, Sophas Samuel S, Matthew Palmer G, and Ancy Jenifer J

    IEEE
    In this article, the problem of using an intelligent system to ensure the use of personal protective equipment (PPE) in industrial safety is discussed. The real-time solution provides fast feedback and easy-to-use monitoring to safety managers and users alike by combining sensors and machine learning algorithms. The analysis shows how it can improve industrial safety regulations and assesses its efficacy. Strategically placed sensors gather copious amounts of data about PPE compliance, and the system integrates wearable, vision-based, and environmental technologies. Novel techniques such as Computer vision algorithm is used object detection and recognition. SSD single-shot multi-box detectors and (YOLO) enable efficient object detection and quick PPE item identification. Furthermore, it has been observed that Region-based Convolution Neural Network(R-CNNs) increase workplace safety standards by improving the system's adaptability to variations in the usage of safety gear over time.

  • Investigations of ScAlN/AlGaN Split Barrier Inspired High Electron Mobility Transistor
    J. S. Raj Kumar, D. Nirmal, H. Victor Du John, and K. Binola Jebalin

    AIP Publishing

  • Investigation on Fe-Doped AlGaN/GaN HEMT at 148 GHz Using E-FPL Technology for High-Frequency Communication Systems
    S. Angen Franklin, Binola K Jebalin I. V, Subhash Chander, Raj Kumar, J. Ajayan, and D. Nirmal

    The Electrochemical Society
    In this research work, design of the Extended Field Plate Length (E-FPL) T-gate with Fe doped AlGaN buffer structure on the graded Aluminum Gallium nitride (AlGaN)/ Gallium nitride (GaN) high electron mobility transistor (HEMT) is proposed. The gate length of 60 nm with an ExFPL up to 50 nm towards the drain shows remarkable improvement in breakdown voltage. Meanwhile, the drain current (IDS) and transconductance (GM) is further improved by the Fe doped AlGaN Buffer design. In radio frequency (RF) small signal analysis this device exhibits a peak current-gain cutoff frequency fT of 148 GHz. This device has improved transconductance of 24% with high frequency has compared with conventional GaN HEMT device. It is highly compatible with military applications such as Radio Frequency (RF) upstream transmitters, ship and aircraft communication transmitters and High-frequency Radars (HFRs).

  • Simulation Study of Stacked Oxide Layer NCFET for RF Applications
    Navya V S, H. Victor Du John, J.S. Raj Kumar, Angen Franklin, and D. Nirmal

    IEEE
    To validate the suitability for radiofrequency (RF) applications, the characteristics of the proposed Ga<inf>2</inf>O<inf>3</inf> based Negative Capacitance Field Effect Transistor (NCFET) with a stacked ferroelectric HfO<inf>2</inf> and Al<inf>2</inf>O<inf>3</inf> gate dielectrics is simulated and studied using TCAD simulation platform. The key Parameters used to investigate the proposed device’s RF performance include intrinsic capacitances (C<inf>gs</inf> & C<inf>gd</inf>), transconductance (g<inf>m</inf>) and the results attained for the proposed device is analyzed. The findings of this work recommends that the proposed Ga<inf>2</inf>O<inf>3</inf> based stacked NCFET design will be advantageous for successful device integration because it will offer benefits like a steep slope and reduced supply voltage operation for RF applications.


  • Intensive Study of Field-Plated AlGaN/GaN HEMT on Silicon Substrate for High Power RF Applications
    J. S. Raj Kumar, D. Nirmal, Manish Kumar Hooda, Surinder Singh, J. Ajayan, and L. Arivazhagan

    Springer Science and Business Media LLC

  • Design and Simulation of a T-gated AlGaN/GaN HEMT with Added Mini Field Plate
    J.S. Raj Kumar, D. Nirmal, H. Victor Du John, S. Angen Franklin, and G. Samuel

    IEEE
    The impacts of a HEMT with a 60 nm T-gated mini field plate device are examined in this study research work, along with the DC/RF properties of the device. The implementation of T- Gate field plate along with the Graded barrier layer configuration in the device provides an extreme impact in the drain current (Ids) of the device. A graded channel AlGaN/GaN HEMTs with the implementation of mini field plate (MFP) exhibits with Ids =1.6 A/mm. In the proposed de vice the InAlGaN layer is simulated which enhances breakdown voltage of 96% while maintaining RF performances of the simulated device. The simulated device exhibits breakdown and fT of 98V and 185GHz respectively.

  • Variable thermal resistance model of GaN-on-SiC with substrate scalability
    L. Arivazhagan, D. Nirmal, Subhash Chander, J. Ajayan, D. Godfrey, J. S. Rajkumar, and S. Bhagya Lakshmi

    Springer Science and Business Media LLC

  • AlGaN/GaN HEMT for highly sensitive detection of Bio-molecules using transconductance method
    P Pavan Kumar Reddy, S Bhagya Lakshmi, L Arivazhgan, J S Raj Kumar, and D Nirmal

    IOP Publishing
    Abstract For the first time, AlGaN/GaN HEMT is demonstrated for bio-sensing application using transconductance analysis. A lot of HEMT based biosensors were developed experimentally but very few reported on sensing applications. These devices are ideal for sensing or tracking biomolecule because of the spontaneous and piezoelectric polarization properties. AlGaN/GaN HEMT with nanogap cavity is used to detect different biomolecule like streptavidin, protein and uricase. The sensitivity of AlGaN/GaN HEMT is investigated through drain current (ID) and transconductance(gm) and is analyzed using Technology Computer Aided Design (TCAD) tool. The result shows a noticeable change in drain current on introducing different biomolecules below the gate cavity region. Higher sensitivity was obtained for with Transconductance analysis than with drain current analysis.

  • Self-Heating Analysis of GaN-HEMT for Various Ambient Temperature and Substrate Thickness
    Arivazhagan L, Anwar Hasan Mohammed Jarndal, Subhash Chander, Godfrey D, Raj Kumar J S, S Bhagyalakshmi, Pavan Kumar Reddy, and D. Nirmal

    IEEE
    Impact of substrate thickness on self-heating effect for AlGaN/GaN HEMT is analyzed. Self-heating effect is analyzed using Technology Computer Aided Design (TCAD) simulation. GaN-HEMT with gate width of 1mm and gate length of 0.7 µm is considered for the analysis. In the simulation, substrate thickness is varied from 100 µm to 200 µm to study its impact on self-heating effect and drain current. In addition, the ambient temperature is varied from 300K to 700K and its impact is analyzed. Impact of gate-gate spacing on thermal performance is also analyzed. Furthermore, Kink effect on drain current at VGS=-2V is observed.

  • Modeling of self-heating for AlGaN/GaN HEMT with thermal conductivity degradation effect
    L. Arivazhagan, D. Nirmal, J. Ajayan, D. Godfrey, J. S. Rakkumar, and S. Bhagya Lakshmi

    AIP Publishing
    Model of self-heating for AlGaN/GaN High Electron Mobility Transistor (HEMT) is proposed. In the model, degradation of thermal conductivity effect is included. Model data of the device is obtained using MATLAB. Physical simulation of GaN-HEMT is carried out using Technology Computer Aided Design (TCAD). The model data is compared with the simulation result to validate the model. In the simulation, temperature and defect dependent thermal conductivity is used. The drain current and temperature are analyzed using pulsed I-V simulation. It is found that the proposed model data shows excellent fit with simulation characteristics.Model of self-heating for AlGaN/GaN High Electron Mobility Transistor (HEMT) is proposed. In the model, degradation of thermal conductivity effect is included. Model data of the device is obtained using MATLAB. Physical simulation of GaN-HEMT is carried out using Technology Computer Aided Design (TCAD). The model data is compared with the simulation result to validate the model. In the simulation, temperature and defect dependent thermal conductivity is used. The drain current and temperature are analyzed using pulsed I-V simulation. It is found that the proposed model data shows excellent fit with simulation characteristics.

  • Enhancement of drain current in AlGaN/GaN HEMT using AlN passivation
    L. Arivazhagan, D. Nirmal, J. Ajayan, D. Godfrey, J. S. Rajkumar, and S. Bhagya Lakshmi

    AIP Publishing
    AlGaN/GaN HEMT with AlN passivation is proposed and investigated. Effectiveness of AlN passivation is analyzed and compared with SiN, SiO2, Al2O3, and HfO2 passivation materials. The performance of these passivation materials are analyzed using Technological Computer Aided Design (TCAD) simulation. The potential, polarization charge, energy band diagram of the GaN HEMT are analyzed. GaN device with AlN passivation exhibits higher drain current than other passivation materials. Hence, AlN passivation is an excellent passivation material for GaN-HEMT in higher drive current application.

  • Improved RF and DC performance in AlGaN/GaN HEMT by P-type doping in GaN buffer for millimetre-wave applications
    L. Arivazhagan, D. Nirmal, D. Godfrey, J. Ajayan, P. Prajoon, A.S. Augustine Fletcher, A. Amir Anton Jone, and J.S. Raj Kumar

    Elsevier BV

  • DC and RF Analysis of AlGaN/GaN MOS-HEMT for High Power Application
    J. S. Raj Kumar, D. Nirmal, L. Arivazhagan, and Pratik P Pandit

    IEEE
    A novel AlGaN/GaN metal-oxide-semiconductor High-electron mobility transistor (MOS-HEMT) using Hf02 as a gate dielectric, grown on a silicon substrate was successfully designed and simulated. In this, we have shown the comparison between HEMT and MOS-HEMT, which eventually proves MOS-HEMT is better than HEMT in certain cases. Different Significant study has been made on gate oxides such as SiO2, Gd2O3, Al2O3, etc but Hf02 was proved to be efficient in reduction of leakage current on GaN-based platforms [3], [4]. Here based on the device performance, Ids of MOS-HEMT is 0.25 A at VGS =6 V is comparatively higher than HEMT which is 0.2 A. The resulted MOS-HEMT also shows improved characteristics of drain current 0.38 A at Vgs= 0 and Vds= 5, hip-her than HEMT.

  • DC Performance analysis of AlGaN/GaN HEMT for future High power applications
    Pratik P. Pandit, L. Arivazhagan, P. Prajoon, J.S. Rajkumar, J. Ajayan, and D. Nirmal

    IEEE
    In this work, we analyzed the DC performance of asymmetric AlGaN/GaN High Electron Mobility Transistors (HEMTs) on SiC substarte using Silvaco-TCAD software. The highlights of the proposed HEMT are intrinsic GaN channel, AlN nucleation layer, AIGaN barrier layer and asymmetric gate technology and GaN cap layer. The $\\mathrm {L}_{\\mathrm {g}} = 50$ nm proposed HEMT on SiC substrate exhibits a $\\mathrm {g}_{\\mathrm {m}_{-}\\max }$ of 170 mS/mm and $\\mathrm {I}_{\\mathrm {D}\\mathrm {S}_{-}\\max }$ of 800 mA/mm and breakdown voltage of 550 V. The proposed HEMT on SiC substrate exhibits a threshold voltage of -5V which indicates its D-Mode operation of the device. This excellent DC and breakdown characteristics of the proposed HEMT makes them an excellent candidate for future high power and high frequency applications.

RECENT SCHOLAR PUBLICATIONS

  • A comprehensive review of AlGaN/GaNHigh electron mobility transistors: Architectures and field plate techniques for high power/high frequency applications
    JSR Kumar, HV Du John, IV BinolaKJebalin, J Ajayan, D Nirmal
    Microelectronics Journal, 105951 2023

  • Simulation Study of Stacked Oxide Layer NCFET for RF Applications
    VS Navya, HV Du John, JSR Kumar, A Franklin, D Nirmal
    2023 8th International Conference on Communication and Electronics Systems 2023

  • Investigation on Fe-Doped AlGaN/GaN HEMT at 148 GHz Using E-FPL Technology for High-Frequency Communication Systems
    SA Franklin, S Chander, JSR Kumar, J Ajayan, D Nirmal
    ECS Journal of Solid State Science and Technology 12 (3), 035006 2023

  • Investigation on LG = 50nm Tapered T-Gated AlGaN/GaN HEMT on Silicon Wafer with a fT/fmax of 264/312GHz for beyond 5G (B5G) Applications
    JSR Kumar, D Nirmal, J Ajayan, S Tayal
    Silicon 14 (17), 11315-11322 2022

  • Design and Simulation of a T-gated AlGaN/GaN HEMT with Added Mini Field Plate
    JSR Kumar, D Nirmal, HV Du John, SA Franklin, G Samuel
    2022 3rd International Conference on Electronics and Sustainable 2022

  • Intensive study of field-plated AlGaN/GaN HEMT on silicon substrate for high power RF applications
    JSR Kumar, D Nirmal, MK Hooda, S Singh, J Ajayan, L Arivazhagan
    Silicon, 1-6 2021

  • Variable thermal resistance model of GaN-on-SiC with substrate scalability
    L Arivazhagan, D Nirmal, S Chander, J Ajayan, D Godfrey, JS Rajkumar, ...
    Journal of Computational Electronics 19 (4), 1546-1554 2020

  • AlGaN/GaN HEMT for highly sensitive detection of Bio-molecules using transconductance method
    PPK Reddy, SB Lakshmi, L Arivazhgan, JSR Kumar, D Nirmal
    IOP conference series: materials science and engineering 872 (1), 012048 2020

  • Self-Heating Analysis of GaN-HEMT for Various Ambient Temperature and Substrate Thickness
    L Arivazhagan, AHM Jarndal, S Chander, D Godfrey, RK JS, ...
    2020 5th International Conference on Devices, Circuits and Systems (ICDCS 2020

  • Modeling of self-heating for AlGaN/GaN HEMT with thermal conductivity degradation effect
    L Arivazhagan, D Nirmal, J Ajayan, D Godfrey, JS Rakkumar, SB Lakshmi
    AIP Conference Proceedings 2201 (1) 2019

  • Enhancement of drain current in AlGaN/GaN HEMT using AlN passivation
    L Arivazhagan, D Nirmal, J Ajayan, D Godfrey, JS Rajkumar, SB Lakshmi
    AIP Conference Proceedings 2201 (1) 2019

  • Improved RF and DC performance in AlGaN/GaN HEMT by P-type doping in GaN buffer for millimetre-wave applications
    L Arivazhagan, D Nirmal, D Godfrey, J Ajayan, P Prajoon, ASA Fletcher, ...
    AEU-International Journal of Electronics and Communications 108, 189-194 2019

  • DC and RF Analysis of AlGaN/GaN MOS-HEMT for High Power Application
    JSR Kumar, D Nirmal, L Arivazhagan, PP Pandit
    2019 2nd International Conference on Signal Processing and Communication 2019

  • DC Performance analysis of AlGaN/GaN HEMT for future High power applications
    PP Pandit, L Arivazhagan, P Prajoon, JS Rajkumar, J Ajayan, D Nirmal
    2018 4th International Conference on Devices, Circuits and Systems (ICDCS 2018

  • Investigations of ScAlN/AlGaN split barrier inspired high electron mobility transistor



MOST CITED SCHOLAR PUBLICATIONS

  • Improved RF and DC performance in AlGaN/GaN HEMT by P-type doping in GaN buffer for millimetre-wave applications
    L Arivazhagan, D Nirmal, D Godfrey, J Ajayan, P Prajoon, ASA Fletcher, ...
    AEU-International Journal of Electronics and Communications 108, 189-194 2019
    Citations: 43

  • Intensive study of field-plated AlGaN/GaN HEMT on silicon substrate for high power RF applications
    JSR Kumar, D Nirmal, MK Hooda, S Singh, J Ajayan, L Arivazhagan
    Silicon, 1-6 2021
    Citations: 10

  • AlGaN/GaN HEMT for highly sensitive detection of Bio-molecules using transconductance method
    PPK Reddy, SB Lakshmi, L Arivazhgan, JSR Kumar, D Nirmal
    IOP conference series: materials science and engineering 872 (1), 012048 2020
    Citations: 5

  • Modeling of self-heating for AlGaN/GaN HEMT with thermal conductivity degradation effect
    L Arivazhagan, D Nirmal, J Ajayan, D Godfrey, JS Rakkumar, SB Lakshmi
    AIP Conference Proceedings 2201 (1) 2019
    Citations: 5

  • A comprehensive review of AlGaN/GaNHigh electron mobility transistors: Architectures and field plate techniques for high power/high frequency applications
    JSR Kumar, HV Du John, IV BinolaKJebalin, J Ajayan, D Nirmal
    Microelectronics Journal, 105951 2023
    Citations: 3

  • Investigation on LG = 50nm Tapered T-Gated AlGaN/GaN HEMT on Silicon Wafer with a fT/fmax of 264/312GHz for beyond 5G (B5G) Applications
    JSR Kumar, D Nirmal, J Ajayan, S Tayal
    Silicon 14 (17), 11315-11322 2022
    Citations: 3

  • Variable thermal resistance model of GaN-on-SiC with substrate scalability
    L Arivazhagan, D Nirmal, S Chander, J Ajayan, D Godfrey, JS Rajkumar, ...
    Journal of Computational Electronics 19 (4), 1546-1554 2020
    Citations: 3

  • Self-Heating Analysis of GaN-HEMT for Various Ambient Temperature and Substrate Thickness
    L Arivazhagan, AHM Jarndal, S Chander, D Godfrey, RK JS, ...
    2020 5th International Conference on Devices, Circuits and Systems (ICDCS 2020
    Citations: 3

  • DC Performance analysis of AlGaN/GaN HEMT for future High power applications
    PP Pandit, L Arivazhagan, P Prajoon, JS Rajkumar, J Ajayan, D Nirmal
    2018 4th International Conference on Devices, Circuits and Systems (ICDCS 2018
    Citations: 3

  • Design and Simulation of a T-gated AlGaN/GaN HEMT with Added Mini Field Plate
    JSR Kumar, D Nirmal, HV Du John, SA Franklin, G Samuel
    2022 3rd International Conference on Electronics and Sustainable 2022
    Citations: 1

  • Enhancement of drain current in AlGaN/GaN HEMT using AlN passivation
    L Arivazhagan, D Nirmal, J Ajayan, D Godfrey, JS Rajkumar, SB Lakshmi
    AIP Conference Proceedings 2201 (1) 2019
    Citations: 1

  • DC and RF Analysis of AlGaN/GaN MOS-HEMT for High Power Application
    JSR Kumar, D Nirmal, L Arivazhagan, PP Pandit
    2019 2nd International Conference on Signal Processing and Communication 2019
    Citations: 1