Peng Yan, Y. Xianglong, Cheng Xiufang, Hu Xiaobo, Xu Xiangang, Yu Peng, W. Ruiqi
{"title":"Theoretical investigation on surface kinetics of the SiC single crystal growth","authors":"Peng Yan, Y. Xianglong, Cheng Xiufang, Hu Xiaobo, Xu Xiangang, Yu Peng, W. Ruiqi","doi":"10.1109/IFWS.2016.7803749","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803749","url":null,"abstract":"According to the BCF theory, a simple surface diffusion model of SiC single crystal was established, and the key parameters such as the surface diffusion length, the critical nucleation and growth rate were obtained by theoretical calculation. The results show that surface diffusion length is 460nmat 2400K and it decreases with the rise of temperature. The relationship between the critical nucleation and the temperature was analyzed. For silicon surface, the critical saturation is decreased with the increase of temperature. Compared with silicon surface, the critical saturation of carbon surface is smaller and almost constant with the increase of temperature. That means, under the same saturation, two-dimensional nucleation occurs on the carbon surface. The growth rate of SiC was obtained using the surface diffusion length, the critical saturation and chemical equilibrium constant of reaction system. And the value was in agreement with the experimental results.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127564746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Minhan Mi, Meng Zhang, Yunlong He, Xiao-hua Ma, Y. Hao
{"title":"The improvement of breakdown voltage in AlGaN/GaN HEMT by using high-k dielectric La2O3 passivation","authors":"Minhan Mi, Meng Zhang, Yunlong He, Xiao-hua Ma, Y. Hao","doi":"10.1109/IFWS.2016.7803771","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803771","url":null,"abstract":"The AlGaN/GaN high electron mobility transistor using 30-nm ALD La<inf>2</inf>O<inf>3</inf> passivation has been fabricated. Compared with the non-passivation HEMT, the breakdown voltage Vbr of La<inf>2</inf>O<inf>3</inf> passivation HEMT can be improved from 115 V to 134 V. 2-D simulation is adopted to explain the phenomenon. The reason for enhanced Vbr in La<inf>2</inf>O<inf>3</inf> passivation HEMT is due to high permittivity e<inf>r</inf> of La<inf>2</inf>O<inf>3</inf> dielectric with drain side wall and AlGaN/GaN HEMT can form metal-insulator-semiconductor (MIS) structure which can modulate electric field distribution. Based on the results, the introduction of high-K dielectric passivation can enhance breakdown voltage as well as simplify the process step.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124303629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Song Yang, Zhikai Tang, Yunyou Lu, Q. Jiang, Anping Zhang, K. J. Chen
{"title":"Role of shallow surface traps and polarization charges in nitride-based passivation for AlGaN/GaN heterojunction FET","authors":"Song Yang, Zhikai Tang, Yunyou Lu, Q. Jiang, Anping Zhang, K. J. Chen","doi":"10.1109/IFWS.2016.7803763","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803763","url":null,"abstract":"In this work, we investigated the mechanisms of nitride-based passivation (i.e. SiNx and AlN) and their impact on high-voltage switching of AlGaN/GaN heterojunction power transistors with TCAD simulations. It was found that they play a vital role for nitride-passivated devices to simultaneously achieve low dynamic ON-resistance (Ron) and uncompromised breakdown capability. Simulated 2-D electrostatic OFF-state potential distributions and RON transients after switching suggested that the polarization charges together with fast-response shallow traps situated at the passivation/gap interface would improve the dynamic RON stability and at the same time effectively lower electric fields at the drain-side gate edge. The difference between SiNx and AlN as surface passivant for GaN HEMTs were also analyzed.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123746253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of thermal annealing on AlGaN/GaN HEMT by fluorine plasma treatment","authors":"Yunlong He, Minhan Mi, Meng Zhang, Chong Wang, Xiao-hua Ma, Y. Hao","doi":"10.1109/IFWS.2016.7803772","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803772","url":null,"abstract":"The influence of thermal annealing on four kinds of AlGaN/GaN high electron mobility transistors (HEMTs) with different fluorine plasma treatment power were compared and analyzed in detail. A thin fluorinated layer between the Schottky metal and the AlGaN barrier layer which produced with fluorine plasma treatment was conformed by the comparison of Schottky reverse gate leakage current before annealing and after annealing. The maximum saturation current and the peak transconductance of HEMTs decreased with the fluorine plasma treatment power increasing before annealing, and they were recovered partially after annealing. The hysteresis of double sweep curves by fluorine plasma treatment was enlarged. F− ions could introduce the acceptor state in the barrier layer, and high temperature could eliminate some trap states introduced by fluorine plasma treatment.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116484226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Sun, Xiufang Chen, Fusheng Zhang, Cancan Yu, Xian Zhao, Xiangang Xu, Yong Zhang, Ruiqi Wang
{"title":"Graphene-assisting photo-electrochemical etching of 4H-SiC","authors":"Li Sun, Xiufang Chen, Fusheng Zhang, Cancan Yu, Xian Zhao, Xiangang Xu, Yong Zhang, Ruiqi Wang","doi":"10.1109/IFWS.2016.7803748","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803748","url":null,"abstract":"With the assistance of in-situ grown graphene on the wafers, semi-insulating 4H-SiC wafers were etched in aqueous KOH using photo-electrochemical method. The etching rate was estimated to be at about 50nm/min. By the cross-sectional scanning electron microscope (SEM) images, triangular structure in a similar size and aligned in the same direction was found on (1–100) face. Whereas on the (11–20) faces, pore channels along with [0001] direction exhibitedat the same time. Furthermore, the structure of 4H-SiC and epitaxial graphene on 4H-SiC (0001) face were respectively constructed with the purpose of figuring out the influence of graphene on the process of SiC etching. The electronic structures and electron density were calculated by first principle theory. When SiC was covered by graphene on the top, the intrinsic indirect wide band gap disappeared, though taking over by the single layer graphene characteristic Dirac cone at the Gama point and the linear dispersion representing buffer layer. In addition, predominately contribution at valence band maximum (VBM) and conduction band minimum (CBM) also changed by comparing the distribution of density of state (DOS).","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123779292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. L. Fang, X. Song, Z. Feng, J. Y. Yin, Z. R. Zhang, B. Wang, Y. M. Guo, Y. Wang, Y. Lv, S. Cai
{"title":"High linearity step-graded AlGaN/GaN heterojunction field effect transistor","authors":"Y. L. Fang, X. Song, Z. Feng, J. Y. Yin, Z. R. Zhang, B. Wang, Y. M. Guo, Y. Wang, Y. Lv, S. Cai","doi":"10.1109/IFWS.2016.7803768","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803768","url":null,"abstract":"We designed and fabricated the AlGaN/GaN HFETs with step graded heterostructure in this work. Compared with the AlGaN/GaN HFETs with linearly graded layer, the AlGaN/GaN HFETs with step graded layer exhibited similar device performance, including the notable wide flat transconductance characteristics. For the AlGaN/GaN step graded heterostructure, each step layer is individual and can be controlled separately during the epi-growth. Especially for the uniformity optimization, the individual growth mode for the AlGaN/GaN step graded heterostructure guarantee the targeted optimization for each layer. It is hoped that this step-graded structure would promote the industrialization of GaN devices in wireless communications applications.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123839414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Simulation and optimization of field limiting rings for ultrahigh voltage 4H-SiC IGBT","authors":"Yang Tongtong, Bai Song, Huang Runhua","doi":"10.1109/IFWS.2016.7803746","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803746","url":null,"abstract":"An ultrahigh voltage 4H-SiC IGBT with field limiting rings termination is designed and simulated using SILVACO TCAD software. Detailed simulations have been performed on field limiting rings, including spacing between rings, width of rings and so on. The simulation results show that the optimized field limiting rings could provide a blocking capability of 20kV. The breakdown voltage with different positive interface charge and negative interface charge densities in consideration have been compared and discussed. The specific key parameters of optimal structure of filed limiting rings have also been presented.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125294606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancement of light extraction on AlGaN-based deep-ultraviolet light-emitting diodes using a sidewall reflection method","authors":"Yanan Guo, Yun Zhang, Jianchang Yan, Xiang Chen, Shuo Zhang, Junxi Wang, Jinmin Li","doi":"10.1109/IFWS.2016.7803775","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803775","url":null,"abstract":"AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) suffer serious light extraction problems. In this work we report a sidewall reflection method to enhance the light extraction of AlGaN-based DUV LEDs. The method includes mesa micro array designs and on-chip high reflective metal pads for DUV light. The 278-nm LEDs using this method show a 30.% improvement in light output power (LOP) compared to LEDs without high reflective metal pads. The dependence of LOP and voltage on micro array mesa size is also investigated. The LOP of the AlGaN-based DUV LED can reach 6.8 mW at 100 mA and nearly 25 mW at 500 mA. The L80 lifetime exceeds 4000 hours.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127368074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenjing Wang, Liuan Li, Liang He, Fan Yang, Zijun Chen, Yue Zheng, Lei He, Zhisheng Wu, Baijun Zhang, Yang Liu
{"title":"Influence of AlGaN back barrier layer thickness on the dynamic ron characteristics of AlGaN/GaN HEMTs","authors":"Wenjing Wang, Liuan Li, Liang He, Fan Yang, Zijun Chen, Yue Zheng, Lei He, Zhisheng Wu, Baijun Zhang, Yang Liu","doi":"10.1109/IFWS.2016.7803761","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803761","url":null,"abstract":"AlGaN back barrier with different thickness is used in AlGaN/GaN high electron mobility transistors (HEMTs) to evaluate the device performances. It shows that a proper AlGaN back barrier thickness (tbb ∼100 nm) is beneficial for obtaining low leakage current and high Ion/Ioff ratio of approximately 108. While further increasing the AlGaN thickness can deteriorate the device performances because of the generation of more surface defects. The dynamic on-resistance (RON) degradation measurements demonstrate that the proper AlGaN back barrier thickness (tbb) can not only improve the 2DEG confinement, but also prevent electrons penetrating into buffer layer. Thus, it results in the reduction of trapping effect and then the improvement of dynamic RON.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122568177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weicheng Zhou, Qing Guo, Xinke Wu, Yi Liu, Kuang Sheng
{"title":"A 1200V/100A all-SiC power module for boost converter of EV/HEV's motor driver application","authors":"Weicheng Zhou, Qing Guo, Xinke Wu, Yi Liu, Kuang Sheng","doi":"10.1109/IFWS.2016.7803751","DOIUrl":"https://doi.org/10.1109/IFWS.2016.7803751","url":null,"abstract":"Motor driver is one of the most important parts in EV and HEV, and power electronics device plays a dominate role in it. Silicon Carbide (SiC) power devices have shown great advantages compared with conventional Si power device for high voltage, high frequency, and high temperature applications, which shows great potential in motor driver applications. In this work, a 1200V/100A all-SiC power module is designed and fabricated. The module is verified in a 19kW boost converter under different ambient temperature, which can be used as the first stage of a motor driver. The measurement results show that this all-SiC power module has a low parasitic parameters. An operating frequency of 100kHz is utilized in the measurement, which shows great potential for the reduction of the volume of motor driver.","PeriodicalId":331453,"journal":{"name":"2016 13th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS)","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124755212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}