scholarly journals Novel High-Energy-Efficiency AlGaN/GaN HEMT with High Gate and Multi-Recessed Buffer

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 444 ◽  
Author(s):  
Shunwei Zhu ◽  
Hujun Jia ◽  
Tao Li ◽  
Yibo Tong ◽  
Yuan Liang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Buffer Layer ◽  
Computer Aided Design ◽  
High Electron Mobility Transistor ◽  
High Energy ◽  
Design System ◽  
High Electron ◽  
Power Added Efficiency ◽  
High Energy Efficiency ◽  
Aided Design

A novel AlGaN/GaN high-electron-mobility transistor (HEMT) with a high gate and a multi-recessed buffer (HGMRB) for high-energy-efficiency applications is proposed, and the mechanism of the device is investigated using technology computer aided design (TCAD) Sentaurus and advanced design system (ADS) simulations. The gate of the new structure is 5 nm higher than the barrier layer, and the buffer layer has two recessed regions in the buffer layer. The TCAD simulation results show that the maximum drain saturation current and transconductance of the HGMRB HEMT decreases slightly, but the breakdown voltage increases by 16.7%, while the gate-to-source capacitance decreases by 17%. The new structure has a better gain than the conventional HEMT. In radio frequency (RF) simulation, the results show that the HGMRB HEMT has 90.8%, 89.3%, and 84.4% power-added efficiency (PAE) at 600 MHz, 1.2 GHz, and 2.4 GHz, respectively, which ensures a large output power density. Overall, the results show that the HGMRB HEMT is a better prospect for high energy efficiency than the conventional HEMT.

scholarly journals Physics-Based TCAD Simulation and Calibration of 600 V GaN/AlGaN/GaN Device Characteristics and Analysis of Interface Traps

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 751
Author(s):  
Yu-Lin Song ◽  
Manoj Kumar Reddy ◽  
Luh-Maan Chang ◽  
Gene Sheu
Keyword(s):  
Conduction Band ◽  
Computer Aided Design ◽  
Measurement Data ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
Device Structure ◽  
Gan Hemt ◽  
Fixed Charges ◽  
Vertical Electric Field ◽  
Aided Design

This study proposes an analysis of the physics-based TCAD (Technology Computer-Aided Design) simulation procedure for GaN/AlGaN/GaN HEMT (High Electron Mobility Transistor) device structures grown on Si (111) substrate which is calibrated against measurement data. The presence of traps and activation energies in the device structure will impact the performance of a device, the source of traps and position of traps in the device remains as a complex exercise until today. The key parameters for the precise tuning of threshold voltage (Vth) in GaN transistors are the control of the positive fixed charges −5 × 1012 cm−2, donor-like traps −3 × 1013 cm−2 at the nitride/GaN interfaces, the energy of the donor-like traps 1.42 eV below the conduction band and the acceptor traps activation energy in the AlGaN layer and buffer regions with 0.59 eV below the conduction band. Hence in this paper, the sensitivity of the trap mechanisms in GaN/AlGaN/GaN HEMT transistors, understanding the absolute vertical electric field distribution, electron density and the physical characteristics of the device has been investigated and the results are in good agreement with GaN experimental data.

A novel 4H-SiC MESFET with multi-recessed p-buffer layer for high energy-efficiency applications

2017 ◽  
Vol 112 ◽  
pp. 97-104 ◽  
Author(s):  
Hujun Jia ◽  
Qiuyuan Wu ◽  
Mei Hu ◽  
Zhihui Yang ◽  
Peimiao Ma ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Buffer Layer ◽  
High Energy ◽  
High Energy Efficiency

scholarly journals Improved MRD 4H-SiC MESFET with High Power Added Efficiency

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 479 ◽  
Author(s):  
Shunwei Zhu ◽  
Hujun Jia ◽  
Xingyu Wang ◽  
Yuan Liang ◽  
Yibo Tong ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Buffer Layer ◽  
High Power ◽  
Computer Aided Design ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Design System ◽  
Power Added Efficiency ◽  
Effect Transistor ◽  
Rf Performance

An improved multi-recessed double-recessed p-buffer layer 4H–SiC metal semiconductor field effect transistor (IMRD 4H-SiC MESFET) with high power added efficiency is proposed and studied by co-simulation of advanced design system (ADS) and technology computer aided design (TCAD) Sentaurus software in this paper. Based on multi-recessed double-recessed p-buffer layer 4H–SiC metal semiconductor field effect transistor (MRD 4H-SiC MESFET), the recessed area of MRD MESFET on both sides of the gate is optimized, the direct current (DC), radio frequency (RF) parameters and efficiency of the device is balanced, and the IMRD MESFET with a best power-added efficiency (PAE) is finally obtained. The results show that the PAE of the IMRD MESFET is 68.33%, which is 28.66% higher than the MRD MESFET, and DC and RF performance have not dropped significantly. Compared with the MRD MESFET, the IMRD MESFET has a broader prospect in the field of microwave radio frequency.

scholarly journals An Improved P-Type Doped Barrier Surface AlGaN/GaN High Electron Mobility Transistor with High Power-Added Efficiency

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1035
Author(s):  
Hujun Jia ◽  
Xiaowei Wang ◽  
Mengyu Dong ◽  
Shunwei Zhu ◽  
Yintang Yang
Keyword(s):  
High Power ◽  
Electron Mobility ◽  
Major Change ◽  
High Electron Mobility Transistor ◽  
High Energy ◽  
High Electron ◽  
High Electron Mobility ◽  
Power Added Efficiency ◽  
Barrier Surface ◽  
P Type

An improved P-type doped barrier surface AlGaN/GaN high electron mobility transistor with high power-added efficiency (PDBS-HEMT) is proposed in this paper. Through the modelling and simulation of ISE-TCAD and ADS software, the influence of the P-type doped region on the performance parameters is studied, and the power-added efficiency (PAE) obtained and effectively improved is further verified. The drain saturation current and the threshold voltage of PDBS-HEMT has no major change compared with the traditional structure; the peak transconductance decreases slightly, but the breakdown voltage is significantly enhanced. Furthermore, the gate-source capacitance and gate-drain capacitance are reduced by 14.6% and 14.3%, respectively. By simulating the RF output characteristics of the device, the maximum oscillation frequency of the proposed structure is increased from 57 GHz to 63 GHz, and the saturated output power density is 10.9 W/mm, 9.3 W/mm and 6.4 W/mm at the frequency of 600 MHz, 1200 MHz and 2400 MHz, respectively. The highest PAE of 88.4% was obtained at 1200 MHz. The results show that the PDBS structure has an excellent power and efficiency output capability. Through the design of the P-type doped region, the DC and RF parameters and efficiency of the device are balanced, demonstrating the great potential of PDBS structure in high energy efficiency applications.

scholarly journals A Silicon-Compatible Synaptic Transistor Capable of Multiple Synaptic Weights toward Energy-Efficient Neuromorphic Systems

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1102 ◽  
Author(s):  
Yu ◽  
Cho ◽  
Park
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Computer Aided Design ◽  
High Reliability ◽  
High Energy ◽  
Short Term ◽  
Synaptic Functions ◽  
Neuromorphic System ◽  
Aided Design

In order to resolve the issue of tremendous energy consumption in conventional artificial intelligence, hardware-based neuromorphic system is being actively studied. Although various synaptic devices for the system have been proposed, they have shown limits in terms of endurance, reliability, energy efficiency, and Si processing compatibility. In this work, we design a synaptic transistor with short-term and long-term plasticity, high density, high reliability and energy efficiency, and Si processing compatibility. The synaptic characteristics of the device are closely examined and validated through technology computer-aided design (TCAD) device simulation. Consequently, full synaptic functions with high energy efficiency have been realized.

scholarly journals New 4H-SiC Metal Semiconductor Field Effect Transistors with Double Symmetric Step Buried Oxide Layer for High Energy Efficiency Applications

2021 ◽  
Author(s):  
Shunwei Zhu ◽  
Hujun Jia ◽  
Mengyu Dong ◽  
Xiaowei Wang ◽  
Yintang Yang
Keyword(s):  
Energy Efficiency ◽  
Electric Field ◽  
Oxide Layer ◽  
Breakdown Voltage ◽  
Field Effect ◽  
Field Effect Transistors ◽  
High Energy ◽  
Power Added Efficiency ◽  
Buried Oxide ◽  
High Energy Efficiency

Abstract A novel 4H-SiC metal semiconductor field effect transistor (MESFET) device with double symmetric step buried oxide layer is proposed and the mechanism is studied through TCAD simulation. The step buried oxide layer is mainly to reduce the current leakage to the substrate and improve drain current. At the same time, the presence of the oxide layer changes the electric field distribution, reduces the electric field concentration phenomenon, and the breakdown voltage is improved. Due to the presence of the step buried oxide layer, the charge distribution of the device is changed, and the frequency characteristics are improved. When the step buried oxide channel is under the optimized parameter condition, compared with the traditional double-recessed structure 4H-SiC MESFET (DR 4H-SiC MESFET), the direct current (DC) characteristics of the new structure are improved, and the breakdown voltage is increased by 14% to reach 183 V. In radio frequency (RF) characteristics, cut-off frequency is 24.4 GHz, an increase of 11.9 %; maximum operating frequency is 63.9 GHz, an increase of 20.3%; the maximum power added efficiency (PAE) in the L-band and S-band reaches 63.5 %, PAE is 23.7 % higher than the DR structure. At the end of this paper, the new structure is verified for high-energy-efficiency, and the results show that the new structure has great potential in high-frequency applications.

Structural Analysis of Product and Computer-Aided Assembly Planning in AssemBL Software Package

2018 ◽  
pp. 11-33
Author(s):  
A. N. Bozhko
Keyword(s):  
Computer Aided Design ◽  
State Of The Art ◽  
Graph Model ◽  
Design System ◽  
Assembly Planning ◽  
Complex Products ◽  
Assembly Sequences ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

Computer-aided design of assembly processes (Computer aided assembly planning, CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. Intensive research on CAAP has been underway since the 1980s. Meanwhile, specialized design systems were created to provide synthesis of assembly plans and product decompositions into assembly units. Such systems as ASPE, RAPID, XAP / 1, FLAPS, Archimedes, PRELEIDES, HAP, etc. can be given, as an example. These experimental developments did not get widespread use in industry, since they are based on the models of products with limited adequacy and require an expert’s active involvement in preparing initial information. The design tools for the state-of-the-art full-featured CAD/CAM systems (Siemens NX, Dassault CATIA and PTC Creo Elements / Pro), which are designed to provide CAAP, mainly take into account the geometric constraints that the design imposes on design solutions. These systems often synthesize technologically incorrect assembly sequences in which known technological heuristics are violated, for example orderliness in accuracy, consistency with the system of dimension chains, etc.An AssemBL software application package has been developed for a structured analysis of products and a synthesis of assembly plans and decompositions. The AssemBL uses a hyper-graph model of a product that correctly describes coherent and sequential assembly operations and processes. In terms of the hyper-graph model, an assembly operation is described as shrinkage of edge, an assembly plan is a sequence of shrinkages that converts a hyper-graph into the point, and a decomposition of product into assembly units is a hyper-graph partition into sub-graphs.The AssemBL solves the problem of minimizing the number of direct checks for geometric solvability when assembling complex products. This task is posed as a plus-sum two-person game of bicoloured brushing of an ordered set. In the paradigm of this model, the brushing operation is to check a certain structured fragment for solvability by collision detection methods. A rational brushing strategy minimizes the number of such checks.The package is integrated into the Siemens NX 10.0 computer-aided design system. This solution allowed us to combine specialized AssemBL tools with a developed toolkit of one of the most powerful and popular integrated CAD/CAM /CAE systems.

Reactions in Activated Peroxide Systems and their Influences on Bleaching Performance

2020 ◽  
Vol 17 ◽  
Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Energy Efficiency ◽  
Textile Industry ◽  
High Energy ◽  
Side Reactions ◽  
Competitive Reactions ◽  
High Energy Efficiency ◽  
Hydrolysis Of ◽  
Bleach Activators

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.

Sign in / Sign up

Export Citation Format

Share Document