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Optimization of InAlAs/InGaAs HEMT Performance for Microwave Frequency Applications and Reliability
Gupta, Ritesh,Aggarwal, Sandeep Kumar,Gupta, Mridula,Gupta, R.S. The Institute of Electronics and Information Engin 2004 Journal of semiconductor technology and science Vol.4 No.3
In the present paper efforts have been made to optimize InAlAs/InGaAs HEMT by enhancing the effective gate voltage ($(V_c-V_off)$) using pulsed doped structure from uniformly doped to delta doped for microwave frequency applications and reliability. The detailed design criteria to select the proper design parameters have also been discussed in detail to exclude parallel conduction without affecting the del ice performance. Then the optimized value of $V_c-V_off$and breakdown voltages corresponding to maximum value of transconductance has been obtained. These values are then used to predict the transconductance and cut-off frequency of the del ice for different channel depths and gate lengths.
Gupta, Ritesh,Aggarwal, Sandeep Kr,Gupta, Mridula,Gupta, R.S. The Institute of Electronics and Information Engin 2006 Journal of semiconductor technology and science Vol.6 No.3
A new analytical model has been proposed for predicting the sheet carrier density of Metal insulator Semiconductor High Electron Mobility Transistor (MISHEMT). The model takes into account the non-linear relationship between sheet carrier density and quasi Fermi energy level to consider the quantum effects and to validate it from subthreshold region to high conduction region. Then model has been formulated in such a way that it is applicable to MESFET/HEMT/MISFET with few adjustable parameters. The model can also be used to evaluate the characteristics for different gate insulator geometries like T-gate etc. The model has been extended to forecast the drain current, conductance and high frequency performance. The results so obtained from the analysis show excellent agreement with previous models and simulated results that proves the validity of our model.
Gupta, Ritesh,Kaur, Ravneet,Aggarwal, Sandeep Kr,Gupta, Mridula,Gupta, R.S. The Institute of Electronics and Information Engin 2010 Journal of semiconductor technology and science Vol.10 No.1
Improvement in breakdown voltage ($BV_{ds}$) and speed of the device are the key issues among the researchers for enhancing the performance of HEMT. Increased speed of the device aspires for shortened gate length ($L_g$), but due to lithographic limitation, shortening $L_g$ below sub-micrometer requires the inclusion of various metal-insulator geometries like T-gate onto the conventional architecture. It has been observed that the speed of the device can be enhanced by minimizing the effect of upper gate electrode on device characteristics, whereas increase in the $BV_{ds}$ of the device can be achieved by considering the finite effect of the upper gate electrode. Further, improvement in $BV_{ds}$ can be obtained by applying field plates, especially at the drain side. The important parameters affecting $BV_{ds}$ and cut-off frequency ($f_T$) of the device are the length, thickness, position and shape of metal-insulator geometry. In this context, intensive simulation work with analytical analysis has been carried out to study the effect of variation in length, thickness and position of the insulator under the gate for various metal-insulator gate geometries like T-gate, $\Gamma$-gate, Step-gate etc., to anticipate superior device performance in conventional HEMT structure.
Gupta, Ritesh,Aggarwal, Sandeep Kumar,Gupta, Mridula,Gupta, R.S. The Institute of Electronics and Information Engin 2007 Journal of semiconductor technology and science Vol.7 No.2
A comprehensive short channel analytical model has been proposed for High Electron Mobility Transistor (HEMT) to obtain higher cut-off frequency maintaining the reliability of the device. The model has been proposed to consider generalized doping variation in the directions perpendicular to and along the channel. The effect of field plates and different gate-insulator geometry (T-gate, etc) have been considered by dividing the area between gate and the high band gap semiconductor into different regions along the channel having different insulator and metal combinations of different thicknesses and work function with the possibility that metal is in direct contact with the high band gap semiconductor. The variation obtained by gate-insulator geometry and field plates in the field and channel potential can be produced by varying doping concentration, metal work-function and gate-stack structures along the channel. The results so obtained for normal device structure have been compared with previous proposed model and numerical method (finite difference method) to prove the validity of the model.
Ritesh Gupta,Ravneet Kaur,Sandeep Kr Aggarwal,Mridula Gupta,R. S. Gupta 대한전자공학회 2010 Journal of semiconductor technology and science Vol.10 No.1
Improvement in breakdown voltage (BVds) and speed of the device are the key issues among the researchers for enhancing the performance of HEMT. Increased speed of the device aspires for shortened gate length (Lg), but due to lithographic limitation, shortening Lg below sub-micrometer requires the inclusion of various metal-insulator geometries like T-gate on to the conventional architecture. It has been observed that the speed of the device can be enhanced by minimizing the effect of upper gate electrode on device characteristics, whereas increase in the BVds of the device can be achieved by considering the finite effect of the upper gate electrode. Further, improvement in BVds can be obtained by applying field plates, especially at the drain side. The important parameters affecting BVds and cut-off frequency (fT) of the device are the length, thickness, position and shape of metal-insulator geometry. In this context, intensive simulation work with analytical analysis has been carried out to study the effect of variation in length, thickness and position of the insulator under the gate for various metal-insulator gate geometries like T-gate, Γ-gate, Step-gate etc., to anticipate superior device performance in conventional HEMT structure.
Optimization of InAlAs/InGaAs HEMT Performance for Microwave Frequency Applications and Reliability
Ritesh Gupta,Sandeep Kumar Aggarwal,Mridula Gupta,R.S.Gupta 대한전자공학회 2004 Journal of semiconductor technology and science Vol.4 No.3
In the present paper efforts have been made to optimize InALs/lnGaAs HEMT by enhancing the effective gate voltage (Vo-Voft) using pulsed doped structure from uniformly doped to delta doped for microwave frequency applications and reliability. The detailed design criteria to select the proper design parameters have also been discussed in detail to exclude parallel conduction without affecting the dewice performance. Then the optimized value of Vo-Voft and breakdown voltages corresponding to maximum value of transconductance has been obtained. These values are then used to predict the transconductance and cut-off frequency of the device for different channel depths and gate lengths.<br/> Index Terms-InAlAs/InGaAs heterostructure, delta doped, uniformly doped, pulsed doped, parallel conduction, channel confinement and breakdown, woltage<br/>
Ritesh Gupta,Sandeep Kr Aggarwal,Mridula Gupta,R. S. Gupta 대한전자공학회 2006 Journal of semiconductor technology and science Vol.6 No.3
A new analytical model has been proposed for predicting the sheet carrier density of Metal insulator Semiconductor High Electron Mobility Transistor (MISHEMT). The model takes into account the non-linear relationship between sheet carrier density and quasi Fermi energy level to consider the quantum effects and to validate it from subthreshold region to high conduction region. Then model has been formulated in such a way that it is applicable to MESFET/HEMT/MISFET with few adjustable parameters. The model can also be used to evaluate the characteristics for different gate insulator geometries like T-gate etc. The model has been extended to forecast the drain current, conductance and high frequency performance. The results so obtained from the analysis show excellent agreement with previous models and simulated results that proves the validity of our model.
The Distribution of the Products of Powers of Generalized Dirichlet Components
Mridula Garg,Vimal Katta,Mahesh Kumar Gupta 경북대학교 자연과학대학 수학과 2002 Kyungpook mathematical journal Vol.42 No.2
In the present paper we establish a generalized Dirichlet distribution and obtain the distirbution of the products of powers of components of the generalized Dirichlet variable. Our findings unify and extend the results given earlier by Rogers and young[3], Rogers[2],Johnson and Kotz[7] and several others.
Linearity-Distortion Analysis of GME-TRC MOSFET for High Performance and Wireless Applications
Malik, Priyanka,Gupta, R.S.,Chaujar, Rishu,Gupta, Mridula The Institute of Electronics and Information Engin 2011 Journal of semiconductor technology and science Vol.11 No.3
In this present paper, a comprehensive drain current model incorporating the effects of channel length modulation has been presented for multi-layered gate material engineered trapezoidal recessed channel (MLGME-TRC) MOSFET and the expression for linearity performance metrics, i.e. higher order transconductance coefficients: $g_{m1}$, $g_{m2}$, $g_{m3}$, and figure-of-merit (FOM) metrics; $V_{IP2}$, $V_{IP3}$, IIP3 and 1-dB compression point, has been obtained. It is shown that, the incorporation of multi-layered architecture on gate material engineered trapezoidal recessed channel (GME-TRC) MOSFET leads to improved linearity performance in comparison to its conventional counterparts trapezoidal recessed channel (TRC) and rectangular recessed channel (RRC) MOSFETs, proving its efficiency for low-noise applications and future ULSI production. The impact of various structural parameters such as variation of work function, substrate doping and source/drain junction depth ($X_j$) or negative junction depth (NJD) have been examined for GME-TRC MOSFET and compared its effectiveness with MLGME-TRC MOSFET. The results obtained from proposed model are verified with simulated and experimental results. A good agreement between the results is obtained, thus validating the model.
Vivek V. Gupta,Nagesh Bhat,Kailash Asawa,Mridula Tak,Salil Bapat,Pulkit Chaturvedi 질병관리본부 2015 Osong Public Health and Research Persptectives Vol.6 No.2
Objectives: A study was conducted with the purpose to assess the knowledge and attitude towards informed consent among private dental practitioners in Bathinda City, Punjab, India. Methods: A cross-sectional survey was conducted among all private dental practitioners in Bathinda City. A self-administered structured questionnaire consisting of 14 items was used to assess their knowledge and attitude regarding informed consent. The response format was based on a 3-point Likert scale. Oneway analysis of variance, independent sample t test, and stepwise multiple linear regression analysis were utilized for statistical analysis. Confidence level and level of significance were set at 95% and 5%, respectively. Results: The mean scores for knowledge and attitude were 19.37 ± 31.82 and 9.40 ± 1.72, respectively. Analysis revealed that qualification and years of experience was statistically significant among both dependent variables (p ≤ 0.05). Conclusion: An unbalanced knowledge of informed consent among the current dentists has suggested the need for awareness programs to fill the knowledge gaps and instill positive attitudes.