Life prediction of next generation power semiconductors in space environment

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K19769
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 60040:Computer system-related
• Research Institution: Kyoto Institute of Technology
• Principal Investigator: Furuta Jun 京都工芸繊維大学, 電気電子工学系, 助教 (30735767)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 放射線 / SiCパワー半導体 / トータルドーズ効果

Outline of Final Research Achievements

SiC MOSFETs, the next-generation semiconductors, were irradiated with gamma rays to evaluate the total dose effect, and SiC MOSFETs were found to have higher tolerance to total dose effect than Si MOSFETs. In particular, SiC planar MOSFETs showed higher radiation tolerance, the threshold voltage changed by only -0.5 V against 150 krad of gamma radiation.
A high voltage was applied to the gate terminals of the devices degraded by the total dose effect to measure the effect of BTI, which is degradation over time. As a result, it was confirmed that SiC MOSFETs fully recovered from degradation due to the total dose effect by applying gate voltage of 46 V.

Free Research Field

半導体の信頼性

Academic Significance and Societal Importance of the Research Achievements

次世代パワー半導体であるSiC MOSFETはSI半導体と比較して高速な動作が可能であり、電力変換回路の小型軽量化が可能である。本研究成果によりSiC MOSFETを宇宙空間で用いることは人工衛星小型軽量化のみでなく、長寿命化にも寄与することができることが分かった。また、SiC trench MOSFETではゲート端子に高電圧を印加することでトータルドーズ効果による回復が可能であるため、定期的に高い電圧を印加することでさらなる長寿命化が可能である。