Search

Your search keyword '"Hu, Long"' showing total 18 results
Start Over Author "Hu, Long" Journal ieee transactions on electron devices
18 results on '"Hu, Long"'

11. Single-Mask Implantation-Free Technique Based on Aperture Density Modulation for Termination in High-Voltage SiC Thyristors

Author

Qing Guo, Hongyi Xu, Kuang Sheng, Hengyu Wang, Na Ren, and Hu Long

Subjects
010302 applied physics, Materials science, business.industry, Aperture, Thyristor, High voltage, 01 natural sciences, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, chemistry, Modulation, Etching, 0103 physical sciences, Silicon carbide, Optoelectronics, Breakdown voltage, Electrical and Electronic Engineering, business, Voltage
Abstract

For the termination in high-voltage SiC thyristor, this article proposes a single-mask implantation-free solution named aperture density modulation technique. Using this technique, the etching profile on the epitaxial layer can be controlled by the aperture layout on the mask. Thus, it can directly form the smoothly tapered junction termination extension with customizable slope profile. The experiments confirm this control ability on profiles with the extension length from 200 to 400 ${\mu } \text{m}$ . The fabricated devices with the blocking voltage near 8 kV (~80%) demonstrate the feasibility as a termination technique. The numerical simulations present the potential to maintain this breakdown voltage within 120 ${\mu } \text{m}$ . Therefore, a low-cost solution for high-voltage termination in SiC bipolar devices is expected using this technique.

Published
2021
Full Text
View/download PDF

13. Si3 N4 Passivation and Side Illumination of High-Power Photoconductive Semiconductor Switch Based on Free-Standing SI-GaN

Author

Yang, Xianghong, Hu, Long, Liu, Jingliang, Duan, Xue, Li, Xin, Liu, Weihua, and Han, Chuanyu

Abstract

To meet the needs of wide band gap (WBG) gallium nitride (GaN)-based photoconductive semiconductor switch (PCSS) in high-voltage and high-power microwave systems. Herein, silicon nitride (Si3N4) dielectric films were deposited on GaN PCSS using plasma-enhanced chemical vapor deposition (PECVD) and illuminated from the side of the device. A high refractive index of 2.03 and a high permittivity of 7.97 were obtained from Si3N4 films, which are characterized by high optical and dielectric properties. According to the electrostatic field simulation, Si3N4’s high permittivity minimizes the peak electric field at the electrode boundary of GaN PCSSs. When the 532-nm incident light is side illuminated for the device, the output peak power and rise time are 59.8 kW and 0.52 ns, respectively. At a future date, the proposed GaN-based PCSS will have a practical application for radio frequency microwave systems.

Published
2023
Full Text
View/download PDF

15. Low Specific Contact Resistivity of 10−3Ω·cm2 for Ti/Al/Ni/Au Multilayer Metals on SI-GaN:Fe Substrate

Author

Yang, Xianghong, Hu, Long, Dang, Xin, Li, Xin, Liu, Weihua, Han, Chuanyu, and Li, Song

Abstract

For the application of third-generation compound semiconductors based on high-voltage, high-power, and high-frequency devices, particularly in photoconductive semiconductor switches (PCSSs), the ohmic contact preparation technology on semi-insulating substrates is crucial. However, iron-doped semi-insulating gallium nitride (SI-GaN:Fe) with low carrier concentration and high bulk resistivity has a very difficult time achieving good ohmic contact characteristics. Here, we have demonstrated preliminary results on an interesting class of good ohmic contact of Ti/Al/Ni/Au on Ga-face of SI-GaN:Fe. The results indicated that the Ti and Al thickness ratio is a critical parameter when determining the optimum annealing temperature and time for ohmic contact. With alloyed Ti/Al/Ni/Au stacks of 20 nm/120 nm/55 nm/45 nm on SI-GaN:Fe after annealing at 850 °C for 35 s in N2 atmosphere, a low specific contact resistivity of $10^{-3}\,\,\Omega \cdot $ cm2 is achieved. At a future date, such excellent ohmic contact characteristics can be applied to the SI-GaN:Fe-based high-power PCSS.

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results