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

• 来源期刊: 中国物理B（英文版）
• 关键词: silicon carbide light triggered thyristor 7-shaped doping profile turn-on delay
• 年，卷（期）: 2018,（10）
• 页码范围: 701-707
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/10/108502

摘要

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 turn-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 turn-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.