scholarly journals A Novel 4H-SiC MESFET with a Heavily Doped Region, a Lightly Doped Region and an Insulated Region

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 488
Author(s):  
Hujun Jia ◽  
Mengyu Dong ◽  
Xiaowei Wang ◽  
Shunwei Zhu ◽  
Yintang Yang

A novel 4H-SiC MESFET was presented, and its direct current (DC), alternating current (AC) characteristics and power added efficiency (PAE) were studied. The novel structure improves the saturation current (Idsat) and transconductance (gm) by adding a heavily doped region, reduces the gate-source capacitance (Cgs) by adding a lightly doped region and improves the breakdown voltage (Vb) by embedding an insulated region (Si3N4). Compared to the double-recessed (DR) structure, the saturation current, the transconductance, the breakdown voltage, the maximum oscillation frequency (fmax), the maximum power added efficiency and the maximum theoretical output power density (Pmax) of the novel structure is increased by 24%, 21%, 9%, 11%, 14% and 34%, respectively. Therefore, the novel structure has excellent performance and has a broader application prospect than the double recessed structure.

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 35
Author(s):  
Hujun Jia ◽  
Yuan Liang ◽  
Tao Li ◽  
Yibo Tong ◽  
Shunwei Zhu ◽  
...  

A 4H-SiC metal semiconductor field effect transistor (MESFET) with layered doping and undoped space regions (LDUS-MESFET) is proposed and simulated by ADS and ISE-TCAD software in this paper. The structure (LDUS-MESFET) introduced layered doping under the lower gate of the channel, while optimizing the thickness of the undoped region. Compared with the double-recessed 4H-SiC MESFET with partly undoped space region (DRUS-MESFET), the power added efficiency of the LDUS-MESFET is increased by 85.8%, and the saturation current is increased by 27.4%. Although the breakdown voltage of the device has decreased, the decrease is within an acceptable range. Meanwhile, the LDUS-MESFET has a smaller gate-source capacitance and a large transconductance. Therefore, the LDUS-MESFET can better balance DC and AC characteristics and improve power added efficiency (PAE).


2013 ◽  
Vol 756-759 ◽  
pp. 4267-4270
Author(s):  
Zhao Huan Tang ◽  
Bin Wang ◽  
Jia Nan Wang ◽  
Kai Zhou Tan

A novel structure of a VDMOS in reducing on-resistance is proposed and experimentally demonstrated with a 200V N-channel VDMOS. With this structure, the on-resistance value of the VDMOS is reduced by 19.6% than that of a traditional VDMOS structure as the breakdown voltage almost maintained the same value, and there is only one additional mask in processing this new structure VDMOS, which is easily fabricated. By TCAD tool, the specific on-resistance value will reduce by 23%, and the value by 33% will be realized when the device is fabricated in three epitaxies and four buried layers. The novel structure can be widely used in high-voltage VDMOS and BCD areas.


2009 ◽  
Vol 43 (4) ◽  
pp. 537-543 ◽  
Author(s):  
V. G. Mokerov ◽  
A. L. Kuznetsov ◽  
Yu. V. Fedorov ◽  
A. S. Bugaev ◽  
A. Yu. Pavlov ◽  
...  

2013 ◽  
Vol 694-697 ◽  
pp. 497-502
Author(s):  
Jiang Tao Gai ◽  
Shou Dao Huang ◽  
Guang Ming Zhou ◽  
Yi Yuan

In order to search after a new way of the propulsion system of tracked vehicle, a novel structure form of electro-mechanical transmission was developed in this paper, through analyzing the advantages and disadvantages of existing projects of electric drive system for tracked vehicle. It could increase the rate of power exertion obviously and synthesize the mechanical and electrical strongpoint. And based on the structure form, an electro-mechanical transmission was designed with double electromotor added planetary mechanism of steering power coupling and gearshift, considering engineering realization. And then straight-line driving and steering performances of the transmission were calculated which proved that the novel electro-mechanical transmission could meet the requirement of tracked vehicle propulsion well.


2009 ◽  
Vol 1203 ◽  
Author(s):  
Paolo Calvani ◽  
Maria Cristina Rossi ◽  
Gennaro Conte ◽  
Stefano Carta ◽  
Ennio Giovine ◽  
...  

AbstractEpitaxial diamond films were deposited on polished single crystal Ib type HPHT diamond plates of (100) orientation by microwave CVD. The epilayers were used for the fabrication of surface channel MESFET structures having sub-micrometer gate length in the range 200-800 nm. Realized devices show maximum drain current and trasconductance values of about 190 mA/mm and 80 mS/mm, respectively, for MESFETs having 200 nm gate length. RF performance evaluation gave cut off frequency of about 14 GHz and maximum oscillation frequency of more than 26 GHz for the same device geometry.


Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Meisam Tahmasbi ◽  
Farhad Razaghian ◽  
Sobhan Roshani

Abstract This paper presents a novel structure of Hybrid Power Amplifier (HPA) to operate in two arbitrary classes of operation at two desirable frequencies. The proposed HPA is designed in concurrent F&F−1 classes, simultaneously for 5G application. Presented HPA can solve the harmonics interference problem for concurrent F and F−1 classes and also for any arbitrary class of operation in desired frequencies. The designed HPA operates at 1.5 GHz frequency in the F class mode, while operates at 2.1 GHz frequency in the F−1 class mode. A new method is presented by using two diplexers to provide two paths for signal in different frequencies. Two parallel paths are used at the output of the HPA circuit, so the proposed HPA can operate at two classes. Two diplexers are used in the HPA to make proper isolation between the designed paths. In design of the proposed HPA, according to the utilized diplexers, the amplifier can operate between two arbitrary classes of operation at desired frequencies without any specific switch. The measured drain efficiency (DE) and power added efficiency (PAE) parameters are 57 and 51%, respectively at 2.1 GHz, while measured DE and PAE are 64 and 54%, respectively at 1.5 GHz.


Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 573 ◽  
Author(s):  
Hujun Jia ◽  
Mei Hu ◽  
Shunwei Zhu

An improved ultrahigh upper gate 4H-SiC metal semiconductor field effect transistor (IUU-MESFET) is proposed in this paper. The structure is obtained by modifying the ultrahigh upper gate height h of the ultrahigh upper gate 4H-SiC metal semiconductor field effect transistor (UU-MESFET) structure, and the h is 0.1 μm and 0.2 μm for the IUU-MESFET and UU-MESFET, respectively. Compared with the UU-MESFET, the IUU-MESFET structure has a greater threshold voltage and trans-conductance, and smaller breakdown voltage and saturation drain current, and when the ultrahigh upper gate height h is 0.1 μm, the relationship between these parameters is balanced, so as to solve the contradictory relationship that these parameters cannot be improved simultaneously. Therefore, the power added efficiency (PAE) of the IUU-MESFET structure is increased from 60.16% to 70.99% compared with the UU-MESFET, and advanced by 18%.


2019 ◽  
Vol 1 (1) ◽  
pp. 43-56
Author(s):  
Siti Rukiyah

This study discusses in depth about the moral values of responsibility in the novel Laskar Pelangi. Furthermore, the proposed related to the socio-cultural background of the authors in the creation of novel Laskar Pelangi effect on moral values. In addition, also discussed the author's view of the world related to the teachings of the value of responsibility. This research uses a qualitative approach with content analysis method. The results showed that the value of responsibility based on the novel structure consisting of man's relationship to himself, namely in terms of character and characterization. The characters are displayed Andrea Hirata bring the characters responsible for the thoughts, attitudes, and behavior. From a review of genetic structuralism, the value of responsibility based on social and cultural background, knowledge systems also influence the social and cultural life. Belitung people's livelihood systems are revealed also shape the character responsible. The author's world view of morals includes the value of self-existence, self-esteem, self-confidence, fear, longing, and responsibility.


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