Digital Commons Network^™

Antimicrobial Properties Of Nanorods: Killing Bacteria Via Impalement, Md. Iftekhar Hossain, Jarrod Edwards, James Tyler, John Anderson, Supriyo Bandyopadhyay

Electrical and Computer Engineering Publications

Silver is known to possess anti-microbial properties that are of chemical origin. It is believed that either Ag atoms bind to thiol groups in bacterial enzymes or Ag+ ions enter bacterial cells and denature the DNA molecule to kill bacteria. Silver nanorods, however, may kill bacteria by another mechanism: it is possible that the sharp tips of the nanorods puncture bacterial cells and kill bacteria via impalementa physical mechanism. To test if this can indeed happen, we have compared the anti-microbial properties of silver and CdS nanorods. No significant difference is found between the two even though CdS does not …

Image Processing With Dipole-Coupled Nanomagnets: Noise Suppression And Edge Enhancement Detection, Md Ahsanul Abeed, Ayan Kumar Biswas, Mamun Al-Rashid, Jayasimha Atulasimha, Supriyo Bandyopadhyay

Electrical and Computer Engineering Publications

Hardware-based image processing offers speed and convenience not found in software-centric approaches. Here, we show theoretically that a 2-D periodic array of dipole-coupled elliptical nanomagnets, delineated on a piezoelectric substrate, can act as a dynamical system for specific image processing functions. Each nanomagnet has two stable magnetization states that encode pixel color (black or white). An image containing black and white pixels is first converted to voltage states and then mapped into the magnetization states of a nanomagnet array with magneto-tunneling junctions (MTJs). The same MTJs are employed to read out the processed pixel colors later. Dipole interaction between the …

High-Field Electron Transport In Doped Zno, L. Ardaravičius, O. Kiprijanovič, J. Liberis, M. Ramonas, E. Šermukšnis, A. Matulionis, M. Toporkov, V. Avrutin, Ü. Özgür, H. Morkoç

Electrical and Computer Engineering Publications

Current-voltage characteristics have been measured for ZnO:Ga and Zn:Sb epitaxial layers with electron densities ranging from 1.4x10(17) cm(-3) to 1.1 x 10(20) cm(-3). Two-terminal samples with coplanar electrodes demonstrate virtually ohmic behavior until thermal effects come into play. Soft damage of the samples takes place at high currents. The threshold power (per electron) for the damage is nearly inversely proportional to the electron density over a wide range of electron densities. Pulsed voltage is applied in order to minimize the thermal effects, and thus an average electric field of 150 kV cm(-1) is reached in some samples subjected to 2 …

Development Of A Multi-Objective Evolutionary Algorithm For Strain-Enhanced Quantum Cascade Lasers, Gregory Edward Triplett, David Mueller

Electrical and Computer Engineering Publications

An automated design approach using an evolutionary algorithm for the development of quantum cascade lasers (QCLs) is presented. Our algorithmic approach merges computational intelligence techniques with the physics of device structures, representing a design methodology that reduces experimental effort and costs. The algorithm was developed to produce QCLs with a three-well, diagonal-transition active region and a five-well injector region. Specifically, we applied this technique to AlxGa1􀀀xAs/InyGa1􀀀yAs strained active region designs. The algorithmic approach is a non-dominated sorting method using four aggregate objectives: target wavelength, population inversion via longitudinal-optical (LO) phonon extraction, injector level coupling, and an optical gain metric. Analysis …

Intra- And Inter-Fractional Variation Prediction Of Lung Tumors Using Fuzzy Deep Learning, Seonyeong Park, Suk Jin Lee, Elisabeth Weiss, Yuichi Motai

Electrical and Computer Engineering Publications

Tumor movements should be accurately predicted to improve delivery accuracy and reduce unnecessary radiation exposure to healthy tissue during radiotherapy. The tumor movements pertaining to respiration are divided into intra-fractional variation occurring in a single treatment session and inter- fractional variation arising between different sessions. Most studies of patients' respiration movements deal with intra-fractional variation. Previous studies on inter-fractional variation are hardly mathematized and cannot predict movements well due to inconstant variation. Moreover, the computation time of the prediction should be reduced. To overcome these limitations, we propose a new predictor for intra- and inter-fractional data variation, called intra- and …

Reversible Strain-Induced Magnetization Switching In Fega Nanomagnets: Pathway To A Rewritable, Non-Volatile, Non-Toggle, Extremely Low Energy Straintronic Memory, Hasnain Ahmad, Jayasimha Atulasimha, Supriyo Bandyopadhyay

Electrical and Computer Engineering Publications

We report reversible strain-induced magnetization switching between two stable/metastable states in ~300 nm sized FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. Voltage of one polarity applied across the substrate generates compressive strain in a nanomagnet and switches its magnetization to one state, while voltage of the opposite polarity generates tensile strain and switches the magnetization back to the original state. The two states can encode the two binary bits, and, using the right voltage polarity, one can write either bit deterministically. This portends an ultra-energy-efficient non-volatile “non-toggle” memory.

Energy-Efficient Magnetoelastic Non-Volatile Memory, Ayan K. Biswas, Supriyo Bandyopadhyay, Jayasimha Atulasimha

Electrical and Computer Engineering Publications

We propose an improved scheme for low-power writing of binary bits in non-volatile (multiferroic) magnetic memory with electrically generated mechanical stress. Compared to an earlier idea [N. Tiercelin et al., J. Appl. Phys. 109, 07D726 (2011)], our scheme improves distinguishability between the stored bits when the latter are read with magneto-tunneling junctions. More importantly, the write energy dissipation and write error rate are reduced significantly if the writing speed is kept the same. Such a scheme could be one of the most energy-efficient approaches to writing bits in magnetic non-volatile memory. (C) 2014 AIP Publishing LLC.

Critical Analysis And Remedy Of Switching Failures In Straintronic Logic Using Bennett Clocking In The Presence Of Thermal Fluctuations, Kuntal Roy

Electrical and Computer Engineering Publications

Straintronic logic is a promising platform for beyond Moore's law computing. Using Bennett clocking mechanism, information can propagate through an array of strain-mediated multiferroic nanomagnets, exploiting the dipolar coupling between the magnets without having to physically interconnect them. Here, we perform a critical analysis of switching failures, i.e., error in information propagation due to thermal fluctuations through a chain of such straintronic devices. We solved stochastic Landau-Lifshitz-Gilbert equation considering room-temperature thermal perturbations and show that magnetization switching may fail due to inherent magnetization dynamics accompanied by thermally broadened switching delay distribution. Avenues available to circumvent such issue are proposed. (C) …

Nanowire-Based Frequency-Selective Capacitive Photodetector For Resonant Detection Of Infrared Radiation At Room Temperature, Saumil Bandyopadhyay

Electrical and Computer Engineering Publications

Characteristics of a capacitive infrared photodetector that works at room temperature by registering a change in capacitance upon illumination are reported. If used in an ideal resonant inductor-resistor-capacitor circuit, it can exhibit zero dark current, zero standby power dissipation, infinite detectivity, and infinite light-to-dark contrast ratio. It is also made frequency-selective by employing semiconductor nanowires that selectively absorb photons of energies close to the nanowire's bandgap. Based on measured parameters, the normalized detectivity is estimated to be ∼3 × 10⁷ Jones for 1.6 μm IR wavelength at room temperature.

Excitonic Recombination Dynamics In Non-Polar Gan/Algan Quantum Wells, D. Rosales, B. Gil, T. Bretagnon, B. Guizal, F. Zhang, S. Okur, M. Monavarian, N. Izyumskaya, V. Avrutin, Ü Özgür, H. Morkoç, J. H. Leach

Electrical and Computer Engineering Publications

The optical properties of GaN/Al0.15Ga0.85N multiple quantum wells are examined in 8 K–300 K temperature range. Both polarized CW and time resolved temperature-dependent photoluminescence experiment are performed so that we can deduce the relative contributions of the non-radiative and radiative recombination processes. From the calculation of the proportion of the excitonic population having wave vector in the light cone, we can deduce the variation of the radiative decay time with temperature. We find part of the excitonic population to be localized in concert with the report of Corfdir et al. (Jpn. J. Appl. Phys., Part 2 52, 08JC01 (2013)) in …

Properties Of The Main Mg-Related Acceptors In Gan From Optical And Structural Studies, B. Monemar, P. P. Paskov, G. Pozina, C. Hemmingsson, J. P. Bergman, S. Khromov, V. N. Izyumskaya, V. Avrutin, X. Li, H. Morkoç, H. Amano, M. Iwaya, I. Akasaki

Electrical and Computer Engineering Publications

The luminescent properties of Mg-doped GaN have recently received particular attention, e.g., in the light of new theoretical calculations, where the deep 2.9 eV luminescence band was suggested to be the main optical signature of the substitutional Mg Ga acceptor, thus, having a rather large binding energy and a strong phonon coupling in optical transitions. We present new experimental data on homoepitaxial Mg-doped layers, which together with the previous collection of data give an improved experimental picture of the various luminescence features in Mg-doped GaN. In n-type GaN with moderate Mg doping (<10¹⁸ cm⁻³), the 3.466 eV …

Spectroscopy Studies Of Straincompensated Mid-Infrared Qcl Active Regions On Misoriented Substrates, Gregory Edward Triplett, Justin Grayer, Charles Meyer, Emily Cheng, Denzil Roberts

Electrical and Computer Engineering Publications

In this work, we perform spectroscopic studies of AlGaAs/InGaAs quantum cascade laser structures that demonstrate frequency mixing using strain-compensated active regions. Using a three-quantum well design based on diagonal transitions, we incorporate strain in the active region using single and double well configurations on various surface planes (100) and (111). We observe the influence of piezoelectric properties in molecular beam epitaxy grown structures, where the addition of indium in the GaAs matrix increases the band bending in between injector regions and demonstrates a strong dependence on process conditions that include sample preparation, deposition rates, mole fraction, and enhanced surface diffusion …

Orientation-Dependent Pseudomorphic Growth Of Inas For Use In Lattice-Mismatched Mid-Infrared Photonic Structures, Gregory Edward Triplett, Charles Meyer, Emily Cheng

Electrical and Computer Engineering Publications

In this study, InAs was deposited on GaAs (100) and GaAs (111)B 2 degrees towardssubstrates for the purpose of differentiating the InAs growth mode stemming from strain and then analyzed using in-situ reflection high energy electron diffraction, scanning electron microscopy, Raman spectroscopy, reflectance spectroscopy, and atomic force microscopy. The procession of InAs deposition throughout a range of deposition conditions results in assorted forms of strain relief revealing that, despite lattice mismatch for InAs on GaAs (approximately 7%), InAs does not necessarily result in typical quantum dot/wire formation on (111) surfaces, but instead proceeds two-dimensionally due primarily to the surface orientation.

Degradation In Algan/Gan Heterojunction Field Effect Transistors Upon Electrical Stress: Effects Of Field And Temperature, C. Y. Zhu, F. Zhang, Romualdo A. Ferreyra, U. Ozgur, Hadis Morkoç

Electrical and Computer Engineering Publications

AlGaN/GaN heterojunction field effect transistors (HFETs) with 2 μm gate length were subjected to on-state-high-field (high drain bias and drain current) and reverse-gate-bias (no drain currentand reverse gate bias) stress at room and elevated temperatures for up to 10 h. The resulting degradation of the HFETs was studied by direct current and uniquely phase noise before and after stress. A series of drain and gate voltages was applied during the on-state-high-field and reverse-gate-bias stress conditions, respectively, to examine the effect of electric field on degradation of the HFET devices passivated with SiNx. The degradation behaviors under these two types of …

The Effect Of Stair Case Electron Injector Design On Electron Overflow In Ingan Light Emitting Diodes, F. Zhang, X. Li, S. Hafiz, S. Okur, Vitaliy Avrutin, U. Ozgur, Hadis Morkoç, A. Matulionis

Electrical and Computer Engineering Publications

Effect of two-layer (In0.04Ga0.96N and In0.08Ga0.92N) staircase electron injector (SEI) on quantum efficiency of light-emitting-diodes (LEDs) in the context of active regions composed of single and quad 3 nm double heterostructures (DHs) is reported. The experiments were augmented with the first order model calculations of electron overflow percentile. Increasing the two-layer SEI thickness from 4 + 4 nm up to 20 + 20 nm substantially reduced, if not totally eliminated, the electron overflow in single DH LEDs at low injections without degrading the material quality evidenced by the high optical efficiency observed at 15K and room temperature. The improvement in …

Ultra-Low-Energy Non-Volatile Straintronic Computing Using Single Multiferroic Composites, Kuntal Roy

Electrical and Computer Engineering Publications

The primary impediment to continued downscaling of traditional charge-based electronic devices in accordance with Moore's law is the excessive energy dissipation that takes place in the device during switching of bits. One very promising solution is to utilize multiferroicheterostructures, comprised of a single-domain magnetostrictive nanomagnet strain-coupled to a piezoelectric layer, in which the magnetization can be switched between its two stable states while dissipating minuscule amount of energy. However, no efficient and viable means of computing is proposed so far. Here we show that such single multiferroic composites can act as universal logic gates for computing purposes, which we demonstrate …

Reliability Of Algan/Gan High Electron Mobility Transistors On Low Dislocation Density Bulk Gan Substrate: Implications Of Surface Step Edges, N. Killat, M. Montes Bajo, T. Paskova, K. R. Evans, J. Leach, X. Li, Ü. Özgür, Hadis Morkoç, K. D. Chabak, A. Crespo, J. K. Gillespie, R. Fitch, M. Kossler, D. E. Walker, M. Trejo, G. D. Via, J. D. Blevins, M. Kuball

Electrical and Computer Engineering Publications

To enable gaining insight into degradation mechanisms of AlGaN/GaN high electron mobility transistors, devices grown on a low-dislocation-density bulk-GaN substrate were studied. Gateleakage current and electroluminescence (EL) monitoring revealed a progressive appearance of EL spots during off-state stress which signify the generation of gate current leakage paths.Atomic force microscopy evidenced the formation of semiconductor surface pits at the failure location, which corresponds to the interaction region of the gate contact edge and the edges ofsurface steps.

Acoustically Assisted Spin-Transfer-Torque Switching Of Nanomagnets: An Energy-Efficient Hybrid Writing Scheme For Non-Volatile Memory, Ayan K. Biswas, Supriyo Bandyopadhyay, Jayasimha Atulasimha

Electrical and Computer Engineering Publications

We show that the energy dissipated to write bits in spin-transfer-torque random access memory can be reduced by an order of magnitude if a surface acoustic wave (SAW) is launched underneath the magneto-tunneling junctions (MTJs) storing the bits. The SAW-generated strain rotates the magnetization of every MTJs' soft magnet from the easy towards the hard axis, whereupon passage of a small spin-polarized current through a target MTJ selectively switches it to the desired state with > 99.99% probability at room temperature, thereby writing the bit. The other MTJs return to their original states at the completion of the SAW cycle.

Correlation Between Si Doping And Stacking Fault Related Luminescence In Homoepitaxial M-Plane Gan, S. Khromov, B. Monemar, Vitaliy Avrutin, Hadis Morkoç, L. Hultman, G. Pozina

Electrical and Computer Engineering Publications

Si-doped GaN layers grown by metal organic vapor phase epitaxy on m-plane GaN substrates were investigated by low-temperature cathodoluminescence (CL). We have observed stacking fault (SF) related emission in the range of 3.29–3.42 eV for samples with moderate doping, while for the layers with high concentration of dopants, no CL lines related to SFs have been noted. Perturbation of the SF potential profile by neighboring impurity atoms can explain localization ofexcitons at SFs, while this effect would vanish at high doping levels due to screening.

Microscopic Distribution Of Extended Defects And Blockage Of Threading Dislocations By Stacking Faults In Semipolar (1101)(1101)()(1101)() Gan Revealed From Spatially Resolved Luminescence, S. Okur, S. Metzner, N. Izyumskaya, F. Zhang, Vitaliy Avrutin, C. Karbaum, F. Bertram, J. Christen, Hadis Morkoç, Ü. Özgür

Electrical and Computer Engineering Publications

Spatial distribution of extended defects in semipolar -oriented GaN layers grown on patterned(001) Si substrates with striped grooves of varying width was investigated by optical means only using near-field scanning optical microscopy (NSOM) and cathodoluminescence (CL). A high density of basal and prismatic stacking faults was observed in the c⁻ wings, and the threadingdislocations in c+ wings, which appear as dark patterns in the NSOM and CL images, were found to bend toward the surface during the initial stages of growth. In the case when growingc+ front of GaN made contact with the SiO2 masking layer during growth, stacking …

Strain Induced Variations In Band Offsets And Built-In Electric Fields In Ingan/Gan Multiple Quantum Wells, L. Dong, J. V. Mantese, Vitaliy Avrutin, Ü. Özgür, H. Morkoç, S. P. Alpay

Electrical and Computer Engineering Publications

The band structure, quantum confinement of charge carriers, and their localization affect the optoelectronic properties of compound semiconductor heterostructures and multiple quantum wells (MQWs). We present here the results of a systematic first-principles based density functional theory (DFT) investigation of the dependence of the valence band offsets and band bending in polar and non-polar strain-free and in-plane strained heteroepitaxial In x Ga1- xN(InGaN)/GaN multilayers on the In composition and misfit strain. The results indicate that for non-polar m-plane configurations with [12¯10]InGaN // [12¯10]GaN and [0001]InGaN // [0001]GaN epitaxial alignments, the valence band offset changes linearly from 0 to 0.57 eV …

Enhanced Microwave Dielectric Tunability Of Ba0.5sr0.5tio3 Thin Films Grown With Reduced Strain On Dysco3 Substrates By Three-Step Technique, Hongrui Liu, Vitaliy Avrutin, Congyong Zhu, Ümit Özgür, Juan Yang, Changzhi Lu, Hadis Morkoç

Electrical and Computer Engineering Publications

Tunable dielectric properties of epitaxial ferroelectric Ba_0.5Sr_0.5TiO₃ (BST) thin films deposited on nearly lattice-matched DyScO₃ substrates by radio frequency magnetron sputtering have been investigated at microwave frequencies and correlated with residual compressive strain. To reduce the residual strain of the BST films caused by substrate clamping and improve their microwave properties, a three-step deposition method was devised and employed. A high-temperature deposition at 1068 K of the nucleation layer was followed by a relatively low-temperature deposition (varied in the range of 673–873 K) of the BST interlayer and a high-temperature deposition at 1068 K …

Spectral Distribution Of Excitation-Dependent Recombination Rate In An In0.13ga0.87n Epilayer, K. Jarašiūnas, S. Nargelas, R. Aleksiejūnas, S. Miasojedovas, M. Vengris, S. Okur, H. Morkoç, Ü Özgür, C. Giesen, Ö. Tuna, M. Heuken

Electrical and Computer Engineering Publications

Time-resolved optical techniques of photoluminescence (PL), light-induced transient grating(LITG), and differential transmission spectroscopy were used to investigate carrier dynamics in a single 50-nm thick In_0.13Ga_0.97N epilayer at high photoexcitation levels. Data in wide spectral, temporal, excitation, and temperature ranges revealed novel features in spectral distribution of recombination rates as follows: at low injection levels, an inverse correlation of carrier life time increasing with temperature and diffusivity decreasing with temperature confirmed a mechanism of diffusion-limited nonradiative recombination at extended defects. Carrier dynamics in the spectral region below the absorption edge but ∼70 meV above the PL band …

Optical Studies Of Strain And Defect Distribution In Semipolar (1(1)Over-Bar01) Gan On Patterned Si Substrates, N. Izyumskaya, F. Zhang, S. Okur, T. Selden, V. Avrutin, Ü. Özgür, S. Metzner, C. Karbaum, F. Bertram, J. Christen, H. Morkoç

Electrical and Computer Engineering Publications

Formation of defects in semipolar ( 11¯01 )-oriented GaN layers grown by metal-organic chemical vapor deposition on patterned Si (001) substrates and their effects on optical properties were investigated by steady-state and time-resolved photoluminescence (PL) and spectrally and spatially resolved cathodoluminescence (CL). Near-band edge emission is found to be dominant in the c +-wings of semipolar ( 11¯01 )GaN, which are mainly free from defect-related emission lines, while the c – wings contain a large number of basal stacking faults. When the advancing c+ and c — fronts meet to coalesce into a continuous film, the existing stacking faults contained …

Extending Device Performance In Photonic Devices Using Piezoelectric Properties, Gregory Edward Triplett

Electrical and Computer Engineering Publications

This study focuses on the influence of epi-layer strain and piezoelectric effects in asymmetric GaInAs/GaAlAs action regions that potentially lead to intra-cavity frequency mixing. The theoretical limits for conduction and valence band offsets in lattice-matched semiconductor structures have resulted in the deployment of non-traditional approaches such as strain compensation to extend wavelength in intersubband devices, where strain limits are related to misfit dislocation generation. Strain and piezoelectric effects have been studied and verified using select photonic device designs. Metrics under this effort also included dipole strength, oscillator strength, and offset of energy transitions, which are strongly correlated with induced piezoelectric …

Pseudomorphic Growth Of Inas On Misoriented Gaas For Extending Quantum Cascade Laser Wavelength, Gregory Edward Triplett, Charles Meyer, Emily Cheng, Justin Grayer, David Mueller, Denzil Roberts, Samuel Graham

Electrical and Computer Engineering Publications

The authors have studied the impact of epilayer strain on the deposition of InAs/GaAs on (100) and (111)B with 2 degrees offset toward 2-1-1 surfaces. Consequences of a 7% lattice mismatch between these orientations in the form of three-dimensional growth are less apparent for (111)B with 2 degrees offset toward 2-1-1 surfaces compared to (100). By exploring a range of molecular beam epitaxy process parameters for InAs/GaAs growth and utilizing scanning electron microscopy, atomic force microscopy, and Raman spectroscopy to evaluate the quality of these strained layers, the authors develop empirical models that describe the influence of the process conditions …

Information Processing With Electron Spins, Supriyo Bandyopadhyay

Electrical and Computer Engineering Publications

Information processors process information in a variety of ways. The human brain processes information through a highly interconnected system of neurons and synapses, while a digital computer processes information by having a binary switch toggle on and off in response to a stream of binary bits. The “switch” is the most primitive unit of the modern computer. The better it is (faster, more energy efficient, more reliable, etc.), the more advanced is the computer hardware. Energy efficiency, however, is more important than any other attribute, not so much because energy is costly, but because too much energy dissipation prevents increasing …

An Automated Method For Analysis Of Microcirculation Videos For Accurate Assessment Of Tissue Perfusion, Kayvan Najarian

Electrical and Computer Engineering Publications

Background

Imaging of the human microcirculation in real-time has the potential to detect injuries and illnesses that disturb the microcirculation at earlier stages and may improve the efficacy of resuscitation. Despite advanced imaging techniques to monitor the microcirculation, there are currently no tools for the near real-time analysis of the videos produced by these imaging systems. An automated system tool that can extract microvasculature information and monitor changes in tissue perfusion quantitatively might be invaluable as a diagnostic and therapeutic endpoint for resuscitation.

Methods

The experimental algorithm automatically extracts microvascular network and quantitatively measures changes in the microcirculation. There are …

Metastable State In A Shape-Anisotropic Single-Domain Nanomagnet Subjected To Spin-Transfer-Torque, Kuntal Roy, Supriyo Bandyopadhyay, Jayasimha Atulasimha

Electrical and Computer Engineering Publications

We predict the existence of a metastable magnetization state in a single-domain nanomagnet with uniaxial shape anisotropy. It emerges when a spin-polarized current, which delivers a spin-transfer-torque possessing a field-like component, is injected into the nanomagnet. At a metastable state, the internal torque due to nanomagnet's shape anisotropy cancels the externally applied spin-transfer-torque and hence the nettorque acting on the magnetization becomes zero. Therefore, it prevents spin-transfer-torque from switching the magnetization from one stable state along the easy axis to the other, even in the presence of room-temperature thermal fluctuations.

Degradation And Phase Noise Of Inaln/Aln/Gan Heterojunction Field Effect Transistors: Implications For Hot Electron/Phonon Effects, C. Y. Zhu, M. Wu, C. Kayis, F. Zhang, X. Li, R. A. Ferreyra, A. Matulionis, Vitaliy Avrutin, Umit Ozgur, Hadis Morkoc

Electrical and Computer Engineering Publications

In_15.7%Al_84.3%N/AlN/GaN heterojunctionfield effect transistors have been electrically stressed under four different bias conditions: on-state-low-field stress, reverse-gate-bias stress, off-state-high-field stress, and on-state-high-field stress, in an effort to elaborate on hot electron/phonon and thermal effects. DC current and phase noise have been measured before and after the stress. The possible locations of the failures as well as their influence on the electrical properties have been identified. The reverse-gate-bias stress causes trap generation around the gate area near the surface which has indirect influence on the channel. The off-state-high-field stress and the on-state-high-field stress induce deterioration of the channel, …