一种低功耗4H-SiC IGBT的仿真研究

doi:10.16180/j.cnki.issn1007-7820.2021.01.006

摘要/Abstract

摘要：

针对传统沟槽栅4H-SiC IGBT关断时间长且关断能量损耗高的问题,文中利用Silvaco TCAD设计并仿真了一种新型沟槽栅4H-SiC IGBT结构。通过在传统沟槽栅4H-SiC IGBT结构基础上进行改进,在N ⁺缓冲层中引入两组高掺杂浓度P区和N区,提高了N ⁺缓冲层施主浓度,折中了器件正向压降与关断能量损耗。在器件关断过程中,N ⁺缓冲层中处于反向偏置状态的PN结对N ^-漂移区中电场分布起到优化作用,加速了N ^-漂移区中电子抽取,在缩短器件关断时间和降低关断能量损耗的同时提升了击穿电压。Silvaco TCAD仿真结果显示,新型沟槽栅4H-SiC IGBT击穿电压为16 kV,在15 kV的耐压设计指标下,关断能量损耗低至4.63 mJ,相比传统结构降低了40.41%。

关键词: 4H-SiC, IGBT, 击穿电压, 关断能量损耗, 正向压降, Silvaco TCAD

Abstract:

In this paper, a new trench gate 4H-SiC IGBT structure is designed and simulated by Silvaco TCAD for the problem that the traditional trench gate 4H-SiC IGBT has long turn-off time and high turn-off energy loss. By improving the structure of the conventional trench gate 4H-SiC IGBT, two sets of high doping P and N layers are introduced in the N ⁺ buffer layer to increase the donor concentration of the N ⁺ buffer layer, which compromises the forward voltage drop of the device and turn off the energy loss. The PN junction in the reverse bias state in the N ⁺ buffer layer optimizes the electric field distribution in the N ^-drift region when the device is in the turn-off process, which accelerates the electron extraction in the N ^-drift region and shortenes the turn-off time of the device. This ultimately reduces the turn-off energy loss of the device and increases the breakdown voltage of the device. Silvaco TCAD simulation results show that the new trench gate 4H-SiC IGBT has a breakdown voltage of 16 kV. Compared with the conventional structure with a breakdown voltage of 15 kV, the turn-off energy loss is as low as 4.63 mJ, which is 40.41% lower than the conventional structure.

Key words: 4H-SiC, IGBT, breakdown voltage, turn-off energy loss, forward voltage drop, Silvaco TCAD

中图分类号:

TN312+.3

苏芳文,毛鸿凯,隋金池,林茂,张飞. 一种低功耗4H-SiC IGBT的仿真研究[J]. 电子科技, 2021, 34(1): 31-36.

SU Fangwen,MAO Hongkai,SUI Jinchi,LIN Mao,ZHANG Fei. Simulation Study of a Low Power 4H-SiC IGBT[J]. Electronic Science and Technology, 2021, 34(1): 31-36.

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参数	C-TIGBT	N-TIGBT
P⁺浓度/cm^-3	5×10¹⁹	5×10¹⁹
N⁺浓度/cm^-3	2×10¹⁹	2×10¹⁹
P^-体区浓度/cm^-3	4×10¹⁷	4×10¹⁷
CSL层浓度/cm^-3	1×10¹⁵	1×10¹⁵
P⁺屏蔽层浓度/cm^-3	5×10¹⁸	5×10¹⁸
N^-漂移区浓度/cm^-3	4.5×10¹⁴	4.5×10¹⁴
N⁺缓冲层浓度/cm^-3	1×10¹⁷	1×10¹⁷
P⁺集电极浓度厚度/μm	1	1
半元胞宽度/μm	2.1	2.1
栅极宽度/μm	0.6	0.6
栅极深度/μm	5	5
N^-漂移区厚度/μm	160	160
P区浓度/cm^-3	-	6×10¹⁷
N区浓度/cm^-3	-	6×10¹⁷

参数	参数值	单位
mu1n.caug	40	cm²·Vs^-1
mu2n.caug	950	cm²·Vs^-1
ncritn.caug	2×10¹⁷	cm^-3
deltan.caug	0.73	arbitrary
gamman.caug	-0.76	arbitrary
alphan.caug	0	arbitrary
betan.caug	-2.4	arbitrary
mu1p.caug	53.3	cm²·Vs^-1
mu2p.caug	105.4	cm²·Vs^-1
ncritp.caug	2.2×10¹⁸	cm^-3
deltap.caug	0.7	arbitrary
gammap.caug	0	arbitrary
alphap.caug	0	arbitrary
betap.caug	-2.1	arbitrary
vsatn	2×10⁷	cm²·Vs^-1
vsatp	2×10⁷	cm²·Vs^-1
betan	2	-
betap	1	-