Investigation of Influence of SiN and SiO2 Passivation in Gate Field Plate Double Heterojunction Al0.3Ga0.7N/GaN/Al0.04Ga0.96N High Electron Mobility Transistors

Silicon - This research article reports the operational characteristics of gate field plate double heterojunction (DH) high electron mobility transistors (HEMTs) using SiN (SiO2) passivation...     

60 GHz Double Deck T-Gate AlN/GaN/AlGaN HEMT for V-Band Satellites

Silicon - The influence of double deck T-gate on LG = 0.2 μm AlN/GaN/AlGaN HEMT is analysed in this paper. The T-gate supported with Silicon Nitride provides a tremendous...     

Applicability of Field Plate in Double Channel GaN HEMT for Radio-Frequency and Power-Electronic Applications

Silicon - In the present communication, for the first time, applicability of Field Plate (FP) for Double Channel (DC) AlGaN/GaNHEMT is demonstrated. Impact of design space parameters such as field...     

An Intensive Study on Assorted Substrates Suitable for High JFOM AlGaN/GaN HEMT

Silicon - The performance comparison and the temperature profile of AlGaN/GaN HEMT on different substrates are investigated. It results the maximum drain-source current (IDS) of 1.08 A/mm, 1.04...     

Gate leakage current induced trapping in AlGaN/GaN Schottky-gate HFETs and MISHFETs

This study examined the correlation between the off-state leakage current and dynamic on-resistance (R_ON) transients in AlGaN/GaN heterostructure field-effect transistors (HFETs) with and without a gate insulator under various stress conditions. The R_ON transients in a Schottky-gate HFET (SGHFET) and metal-insulator-semiconductor HFET (MISHFET) were observed after applying various amounts of drain-source bias stress. The gate insulator in the MISHFET effectively reduced the electron injection from the gate, thereby mitigating the degradation in dynamic switching performance. However, at relaxation times exceeding 10 ms, additional detrapping occurred in both the SGHFET and MISHFET when the applied stress exceeded a critical voltage level, 50 V for the SGHFET and 60 V for MISHFET, resulting in resistive leakage current build-up and the formation of hot carriers. These high-energy carriers acted as ionized traps in the channel or buffer layers, which subsequently caused additional trapping and detrapping to occur in both HFETs during the dynamic switching test conducted.     

Performance Improvement of Heterojunction Double Gate TFET with Gaussian Doping

Silicon - A new Ge/SiGe heterojunction double-gate tunnel field effect transistor (DGT) model with hetero dielectric gate and Gaussian doping drain region is investigated for the first time. The...     

Electrical characterization and nanoscale surface morphology of optimized Ti/Al/Ta/Au ohmic contact for AlGaN/GaN HEMT

Good ohmic contacts with low contact resistance, smooth surface morphology, and a well-defined edge profile are essential to ensure optimal device performances for the AlGaN/GaN high electron mobility transistors [HEMTs]. A tantalum [Ta] metal layer and an SiN_x thin film were used for the first time as an effective diffusion barrier and encapsulation layer in the standard Ti/Al/metal/Au ohmic metallization scheme in order to obtain high quality ohmic contacts with a focus on the thickness of Ta and SiN_x. It is found that the Ta thickness is the dominant factor affecting the contact resistance, while the SiN_x thickness affects the surface morphology significantly. An optimized Ti/Al/Ta/Au ohmic contact including a 40-nm thick Ta barrier layer and a 50-nm thick SiN_x encapsulation layer is preferred when compared with the other conventional ohmic contact stacks as it produces a low contact resistance of around 7.27 × 10^-7 Ω·cm² and an ultra-low nanoscale surface morphology with a root mean square deviation of around 10 nm. Results from the proposed study play an important role in obtaining excellent ohmic contact formation in the fabrication of AlGaN/GaN HEMTs.     

Performance Analysis of Heterojunction and Hetero Dielectric Triple Material Double Gate TFET

Silicon - The gate material work function engineering and hetero-dielectric engineering concepts are discussed in this paper to design a novel triple material DG Tunnel FET. The three different...     

Influence of Symmetric Underlap on Analog,RF and Power Applications for DG AlGaN/GaN MOS-HEMT

Silicon - An Underlap Double Gate (U-DG) Symmetric Heterojunction AlGaN/GaN Metal Oxide Semiconductor High Electron Mobility Transistor (MOS-HEMT) with varying source and drain underlap lengths...     

Ultrathin GaN film and AlGaN/GaN heterostructure grown on thick AlN buffer by MOCVD

High-quality AlGaN/GaN/AlN heterostructures with thin GaN channel and thick AlN buffer layer were grown by metal organic chemical vapor deposition (MOCVD) on SiC substrate. By analyzing growth modes of GaN films on AlN buffer layers with different thicknesses, it is revealed that film-forming point of GaN grown on AlN buffer increases with the increase in AlN buffer thickness. Accordingly, new growth model of GaN on AlN buffer was proposed, which shows that there is an optimal matching value between Ga source flow rate and AlN thickness when GaN is grown on AlN buffer of different thicknesses. Under optimal conditions, AlGaN/GaN/AlN heterostructures with 120 nm thin GaN channel layer and thick AlN buffer show excellent carrier-limited domain, high crystalline quality, and good transport properties. Results in this work would be useful for preparing high-quality heterostructures on AlN buffer and high electron mobility transistor (HEMT) devices. Moreover, these findings can also be applied to the growth of other hyperfine structures (quantum wells, superlattices, and digital alloys) in the future.     

A Comprehensive Review on the Single Gate,Double Gate,Tri-Gate,and Heterojunction Tunnel FET for Future Generation Devices

Silicon - Today’s generation of the technological world needs low-power application devices and low-cost transistors. Recently researchers have developed a 3 nm MOSFET...     

Analysis of Thermal Effects on Electrical Characterization of AlGaN/GaN/Si FAT-HEMTs

In this paper we report on the characteristics of Schottky contact behavior of AlGaN/GaN High Electron Mobility Transistors (HEMTs) on a Si Substrate. A variety of electrical techniques such as capacitance-voltage (C-V) and deep level transient spectroscopy (DLTS) measurements have been used to characterize the diode. The behavior of the ideality factor n, the effective barrier height Φ_b, and the series resistance R_S is studied with temperature. C-V measurements successively sweeping up and down the voltage from 0 V to 12 V(absolute value) have demonstrated a hysteresis phenomenon which is more pronounced when the temperature increases. This parasitic effect can be attributed to the presence of traps activated in the Schottky diode. The related deep levels defects which are responsible for parasitic effects, were characterized and extracted by the Deep Level Transient Spectroscopy (DLTS) technique that has been used in previous studies. The identification of these traps showed a correlation between DLTS and C-V measurements.     

Analysis of ONOFIC Technique Using SiGe Heterojunction Double Gate Vertical TFET for Low Power Applications

Silicon - In this paper, a new technique ONOFIC is proposed and implemented for designing the SiGe heterojunction 2D double gate Vertical t-shaped TFET as an inverter circuit for low power...     

Electric Properties of AlGaN/GaN/Si High electron Mobility Transistors

Silicon - This work investigated the electrical properties in AlGaN/GaN/Si HEMTsgrown by molecular beam epitaxy. The electrical behavior have been investigated using by electric permittivity,...     

Charge Density Based Small Signal Modeling for InSb/AlInSb Asymmetric Double Gate Silicon Substrate HEMT for High Frequency Applications

Silicon - This paper proposes the Asymmetric Double Gate Silicon Substrate HEMT (ADG-Si-HEMT) to study the carrier concentration and intrinsic small signal parameters of the InSb/AlInSb silicon...     

Effect of Dual Metal on RF/Analog and Linearity Performance of Double Gate Ferroelectric Si-doped-HfO2 GaN MOSHEMT

Silicon - In this work, the authors have demonstrated and differentiated between various analog/RF and linearity performances of a lattice-matched normally off dual-gate ferroelectric metal oxide...     

双波纹板管式换热器流场的数值模拟

介绍了一种用于气气交换的错流式双波纹板管式换热器,它具有单位体积换热面积大,结构紧凑、稳定性好以及换热系数高等特点.运用Fluent软件.对不同尺寸的双波纹板管式换热器的流场进行了模拟,经过分析对比得到换热效果最佳时双波纹板片的形状.研究结果表明,换热板片上双波纹的波幅、周期和板间距决定了板式换热器的换热效果和压降等.     

Optimization of Device Dimensions of High-k Gate Dielectric Based DG-TFET for Improved Analog/RF Performance

Silicon - The optimization of device dimensions along with high-k gate dielectric is investigated in this work for improving RF/analog performance of double gate (DG) TFET device. Through...     

AlGaN/GaNHEMT氢气传感器室温下响应特性的研究

制作了基于AlGaN/GaN HEMT结构的微型氢气传感器。本文研究了室温条件下栅压与传感器氢气响应特性的关系。研究结果表明随着外加栅压(-2.5 V至0.5 V)的增大,传感器对氢气响应的灵敏度减小,最大灵敏度在阈值电压V_G=-2.5 V处,传感器对25 ppm氢气响应的灵敏度为87.1%,响应时间为15 s。当V_G=-2.5 V,V_(DS)=6 V时,传感器对氢气响应的灵敏度随浓度的升高而增大,且呈对数关系。研究表明Pt/AlGaN/GaN HEMT结构的氢气传感器可应用于室温氢气检测,具有极高的应用潜力。