SiGe을 소스 접합 물질로 사용하는 터널링 전계효과 트랜지스터의 성능 및 짧은 채널 효과 분석

국문 초록 (Abstract)

본 논문에서는 Si 기반의 터널링 전계효과 트랜지스터(tunneling field-effect transistor, TFET)의 낮은 전류 구동 능력을 향상시키기 위해 소스 접합에 Si1-xGex을 적용한 이종접합 기반의 Si1-xGex 터널링 전계효과 트랜지스터의 성능을 분석하고 주어진 소자에서 나타날 수 있는 짧은 채널 효과(short-channel sffects)의 양상을 살펴본다. Ge 함량(x)의 변화에 따른 소스 접합물질의 에너지 밴드갭 변화와 에너지 자리 밀도(density of states)의 변화의 결과로 나타나는 켜진 상태 전류의 변화에 초점을 두어 분석을 수행하였다. 더불어, 향후 10 nm 이하 기술 노드(technology node)에서의 소자 적용 가능성을 확인함과 동시에 짧은 채널에서 나타나는 비이상적인 효과들을 살펴보기 위해 채널 길이(Lch)를 28 nm, 14 nm, 10 nm, 7 nm로 변화시키면서 시뮬레이션을 수행하였다. Lch이 짧아질수록 소스와 드레인 간의 전기장의 겹침으로 채널의 일부 영역에서 인해 펀치스루 (punch-through) 현상이 발행하여 TFET의 스위칭 특성이 열화되는 것을 확인하였다. 나아가, Lch의 변화에 따른 고속 동작특성 변화를 확인하기 위해 fT 및 fmax를 추출하였으며 Lch가 짧아질수록 단조증가하는 경향을 확인하였다.

다국어 초록 (Multilingual Abstract)

In this paper, we present the device performances of Si1-xGex heterojunction tunneling field-effect transistor (TFET) having Si1-xGex source junction specifically designed for improving the rather low on-state current (Ion) of Si TFET and have a look into the short-channel effects (SCEs) which might take place in the device. The analyses are performed with a focus on the relation between Ge fraction (x) and Ion under the influences of changes in energy bandgap and density of states (DOS) in the Si1-xGex source junction as a function of x. Also, in order to evaluate the possibility of application of the Si1-xGex TFET to the upcoming sub-10-nm technology nodes and the non-ideal effects arising from the extremely short-channel TFETs simultaneously, the device simulations were performed with scaling the channel length: 28 nm, 14 nm, 10 nm, and 7 nm. It is confirmed that the switching characteristics of Si1-xGex TFET are degraded as Lch is shrunken, due to the electric field overlap between source and drain in a part of channel leading to punch-through. Furthermore, in order to investigate the high-speed operation characteristics, fT and fmax were extracted from the devices with different Lch’s and it was verified that those parameters maintained the tendency of increase as Lch gets shorter.

목차 (Table of Contents)

• 요약
• Abstract
• Ⅰ. 서론
• Ⅱ. 본론
• Ⅳ. 결론
• REFERENCES

참고문헌 (Reference)

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