,Shortening turn-on delay of SiC light triggered thyristor by 7-shaped thin n-base doping profile

• 作 者: Xi Wang Hong-Bin Pu Qing Liu and Li-Qi An
• 机 构: Department of Electronic Engineering, Xi’an University of Technology, Xi’an 710048, China
• 出 处: 中国物理B（英文版）
• 发表日期: 2018年10期
• 关键词: silicon carbide light triggered thyristor 7-shaped doping profile turn-on delay

A new 4H–SiC light triggered thyristor (LTT) with 7-shaped thin n-base doping profile is proposed and simulated using a two-dimensional numerical method. In this new structure, the bottom region of the thin n-base has a graded doping profile to induce an accelerating electric field and compensate for the shortcoming of the double-layer thin n-base structure in transmitting injected holes. In addition, the accelerating electric field can also speed up the transmission of photon-generated carriers during light triggering. As a result, the current gain of the top pnp transistor of the SiC LTT is further increased. According to the TCAD simulations, the tu-on delay time of the SiC LTT decreases by about 91.5％compared with that of previous double-layer thin n-base SiC LTT. The minimum tu-on delay time of the SiC LTT is only 828 ns, when triggered by 100 mW/cm2 ultraviolet light. Meanwhile, there is only a slight degradation in the forward blocking characteristic.