AlGaN/GaN HEMT의 분극 현상에 대한 3D 시뮬레이션

3D Simulation on Polarization Effect in AlGaN/GaN HEMT

  • 정강민 (고려대학교 전자전기공학과) ;
  • 김재무 (고려대학교 전자전기공학과) ;
  • 김희동 (고려대학교 전자전기공학과) ;
  • 김동호 (고려대학교 전자전기공학과) ;
  • 김태근 (고려대학교 전자전기공학과)
  • Jung, Kang-Min (School of Electrical Engineering, Korea University) ;
  • Kim, Jae-Moo (School of Electrical Engineering, Korea University) ;
  • Kim, Hee-Dong (School of Electrical Engineering, Korea University) ;
  • Kim, Dong-Ho (School of Electrical Engineering, Korea University) ;
  • Kim, Tae-Geun (School of Electrical Engineering, Korea University)
  • 투고 : 2009.10.26
  • 심사 : 2010.04.27
  • 발행 : 2010.10.25

초록

본 논문에서는 AlGaN/GaN HEMT의 분극에 의한 전기적인 특성과 구조적인 특성에 대해서 분석하였다. 몰 분율, AlGaN barrier 층의 두께의 물리적인 변화에 따라서 이차원 전자가스 채널의 농도 변화가 이루어지는 것을 바탕으로 DC 특성 및 분극을 고려한 최적화된 구조에 대해서 시뮬레이션을 진행하였다. AlGaN의 몰 분율이 0.3 몰에서 0.4 몰로 증가할수록 분극에 의한 bound sheet charge가 16 % 증가하며 그에 따라서 Id-Vd 특성 역시 37% 증가하게 된다. 또한 AlGaN 층의 두께가 17 nm에서 38nm로 증가할수록 Id-Vd의 특성이 증가하다가 임계두께인 39nm에 이르게 되면 AlGaN층의 relaxation에 의해서 급격하게 특성이 나빠지는 것을 알 수 있다.

In this paper, we investigated the polarization effects on the electrical and structural characteristics of AlGaN/GaN HEMT. Both the Al mole-fraction and the barrier thickness of AlGaN, which determine the profiles of a two-dimensional electron gas, were simulated to obtain the optimum HEMT structure affecting the polarization effect. As a results, we found that the amount of bound sheet charges was increased by 16% and the maximum drain current density ($I_D$,max) was increased by more than 37%, while AI mole fractions are changed from 0.3 to 0.4. We also observed a 37% improvement in maximum drain current density ($I_D$,max) by increasing AIGaN layer thickness from 17 to 38 nm. However when AlGaN layer thickness reached the critical thickness, DC characteristics were dramatically lowered due to 'bulk' relaxation in AlGaN layer.

키워드

참고문헌

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