KAIST 연구팀, 산화물 수직 채널 트랜지스터 안정성 높이는 절연막 개발

Translation

A research team led by Professor 권지민 of KAIST's School of Electrical Engineering, working with researchers at UNIST, Yonsei University and elsewhere in Korea, has developed a multilayer interlayer insulating film structure that raises the performance and stability of the oxide vertical channel transistor (VCT), a next-generation memory device. A VCT places the channel, the path current flows along in a semiconductor, vertically rather than horizontally, so that semiconductors can be stacked upward. Using an oxide semiconductor as the channel material reduces leakage current and so improves power efficiency. The team used a multilayer insulating film made of silicon nitride, silicon dioxide and silicon nitride to steer oxygen toward the oxide semiconductor, cutting oxygen vacancies while keeping oxygen from moving toward the metal electrode and oxidising it. Even after being switched more than 10 million times, the change in threshold voltage — the point at which the transistor turns on — stopped at 50 millivolts or less. The team also verified performance at the system level by combining the device with conventional silicon-based CMOS semiconductors, and the results were published in the international journal Advanced Functional Materials on May 20 and chosen as a cover paper.