Kim Chaeyun, Yoon Hyowon, Park Yeongeun, Kim Sangyeob, Kang Gyuhyeok, Kim Dong-Seok, Seok Ogyun
Department of Electronic Engineering, Kumoh National Institute of Technology, Gumi-si 39177, Republic of Korea.
Department of Semiconductor System Engineering, Kumoh National Institute of Technology, Gumi-si 39177, Republic of Korea.
Micromachines (Basel). 2024 Apr 4;15(4):496. doi: 10.3390/mi15040496.
We investigated the effects of gate bias regarding the degradation of electrical characteristics during gamma irradiation. Moreover, we observed the punch through failure of 1.2 kV rated commercial Silicon Carbide (SiC) Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) due to the influence of gate bias. In addition, the threshold voltage (V) and on-resistance (R) of the SiC MOSFETs decreased significantly by the influence of gate bias during gamma irradiation. We extracted the concentration of carriers and fixed charge (Q) in oxide using N-type SiC MOS capacitors and Transmission Line Measurement (TLM) patterns to analyze the effects of gamma irradiation. The Total Ionizing Dose (TID) effect caused by high-energy gamma-ray irradiation resulted in an increase in the concentration of holes and Q in both SiC and oxide. To analyze the phenomenon for increment of hole concentration in the device under gate bias, we extracted the subthreshold swing of SiC MOSFETs and verified the origin of TID effects accelerated by the gate bias. The Q and doping concentration of p-well values extracted from the experiments were used in TCAD simulations (version 2022.03) of the planar SiC MOSFET. As a result of analyzing the energy band diagram at the channel region of 1.2 kV SiC MOSFETs, it was verified that punch-through can occur in 1.2 kV SiC MOSFETs when the gate bias is applied, as the TID effect is accelerated by the gate bias.
我们研究了栅极偏置对伽马辐照期间电学特性退化的影响。此外，我们观察到由于栅极偏置的影响，额定电压为1.2 kV的商用碳化硅（SiC）金属氧化物半导体场效应晶体管（MOSFET）出现穿通故障。另外，在伽马辐照期间，由于栅极偏置的影响，SiC MOSFET的阈值电压（V）和导通电阻（R）显著降低。我们使用N型SiC MOS电容器和传输线测量（TLM）图案提取了氧化物中载流子和固定电荷（Q）的浓度，以分析伽马辐照的影响。高能伽马射线辐照引起的总电离剂量（TID）效应导致SiC和氧化物中空穴浓度和Q增加。为了分析栅极偏置下器件中空穴浓度增加的现象，我们提取了SiC MOSFET的亚阈值摆幅，并验证了由栅极偏置加速的TID效应的起源。从实验中提取的p阱值的Q和掺杂浓度用于平面SiC MOSFET的TCAD模拟（2022.03版）。通过分析1.2 kV SiC MOSFET沟道区域的能带图，结果验证了在施加栅极偏置时，1.2 kV SiC MOSFET中可能发生穿通，因为TID效应会被栅极偏置加速。
