Non-ideal effect in 4H-SiC bipolar junction transistor with double Gaussian-doped base  

作　　者：元磊 张玉明 宋庆文 汤晓燕 张义门 

机构地区：[1]Key Laboratory of Wide Band Gap Semiconductor Materials and Devices,School of Microelectronics,Xidian University [2]School of Advanced Materials and Nanotechnology,Xidian University

出　　处：《Chinese Physics B》2015年第6期651-655,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.60876061 and 61234006);the Natural Science Foundation of Shaanxi Province,China(Grant No.2013JQ8012);the Doctoral Fund of the Ministry of Education of China(Grant Nos.20130203120017 and 20110203110010)

摘　　要：The non-ideal effect of 4H-SiC bipolar junction transistor （BJT） with a double Gaussian-doped base is characterized and simulated in this paper. By adding a specific interface model between SiC and SiO2, the simulation results are in good agreement with the experiment data. An obvious early effect is found from the output characteristic. As the temperature rises, the early voltage increases, while the current gain gradually decreases, which is totally different from the scenario of silicon BJT. With the same effective Gummet number in the base region, the double Gaussian-doped base structure can realize higher current gain than the single base BJT due to the built-in electric field, whereas the early effect will be more salient. Besides, the emitter current crowding effect is also analyzed. Due to the low sheet resistance in the first highly- doped base epilayer, the 4H-BJT with a double base has more uniform emitter current density across the base-emitter junction, leading to better thermal stability.The non-ideal effect of 4H-SiC bipolar junction transistor （BJT） with a double Gaussian-doped base is characterized and simulated in this paper. By adding a specific interface model between SiC and SiO2, the simulation results are in good agreement with the experiment data. An obvious early effect is found from the output characteristic. As the temperature rises, the early voltage increases, while the current gain gradually decreases, which is totally different from the scenario of silicon BJT. With the same effective Gummet number in the base region, the double Gaussian-doped base structure can realize higher current gain than the single base BJT due to the built-in electric field, whereas the early effect will be more salient. Besides, the emitter current crowding effect is also analyzed. Due to the low sheet resistance in the first highly- doped base epilayer, the 4H-BJT with a double base has more uniform emitter current density across the base-emitter junction, leading to better thermal stability.

关 键 词：4H-SiC BJT double base early voltage emitter current crowding 

分 类 号：TN322.8[电子电信—物理电子学]