대한전자공학회논문지SD (Journal of the Institute of Electronics Engineers of Korea SD)

대한전자공학회 (The Institute of Electronics and Information Engineers)
권호 표지

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
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

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

  1. 김재무, 김수진, 김동호, 정강민, 최홍구, 한철구, 김태근, "사다리꼴 게이트 구조를 갖는 고내압 AlGaN/GaN HEMT", 대한전자공학회논문지, 제46권 SD편, 제4호, 10쪽-14쪽, 2009년 4월
  2. 오영해, 지순구, 서정하, "압전 및 자발 분극을 고려한 단채널 AlGaN/GaN HEMT의 전류-전압 특성에 관한 해석적 모델", 대한전자공학회논문지, 제42권 SD편, 제12호, 103쪽-112쪽, 2005년 12월
  3. Zhang N Q, Keller S, Parish G, Heikman S, Denbaars S P and Mishra U K, "High breakdown GaN HEMT with overlapping gate structure", IEEE Electron Device Lett. 21, pp. 373-375, September 2000. https://doi.org/10.1109/55.852954
  4. Wu Y F, Saxler A, Moore M, Smith R P, Sheppard S, Chavarkar P M, Wisleder T, Mishra U K and Parikh P, "30-W/mm GaN HEMTs by field plate optimization", IEEE Electron Device Lett. 25, pp. 117-119, March 2004. https://doi.org/10.1109/LED.2003.822667
  5. S.K. Davidsson, M. Gurusinghe, T.G. Andersson and H. Zirath, "The influence of composition and unintentional doping on the two-dimensional electron gas density in AlGaN/GaN heterostructure", Journal of Electronic Materials. 33, pp. 440-444, 2004. https://doi.org/10.1007/s11664-004-0199-2
  6. A. F. M. Answer and Elias W. Faraclas, "AlGaN/GaN HEMTs: Experiment and simulation of DC characteristics", Solid-State Electronics. 50, pp. 1051-1056, June 2006. https://doi.org/10.1016/j.sse.2006.04.014
  7. P.M. Asbeck, E.T. Yu, S.S. Lau, G.J. Sullivan. Van Hove and J. Redwing, "Piezoelectric charge densities in AlGaN/GaN HFETs", Electron. Lett. 3, pp. 1230-1231, June 1997.
  8. Device simulation software Atlas, Atlas User's Manual, Silcvaco international, 2007.
  9. F. Bernardini, V. Fiorentini, and D. Vanderbilt, "Spontaneous polarization and piezoelectric constants of III-V nitrides", Phys. Rev. B. 56, R10024, May 1997. https://doi.org/10.1103/PhysRevB.56.R10024
  10. K. Tsubouchi, K. Sugai, and N. Mikoshiba, IEEE Ultrason. Symp. 1, 375 (1981)
  11. Q. Z. Liu, L. S. Yu, F. Deng, and S. S. Lau, Q. Chen, J. W. Yang, and M. A. Khan, "Study of contact formation in AlGaN/GaN heterostructures", Appl. Phys. Lett. 71, pp. 1658-1660, September 1997. https://doi.org/10.1063/1.119786
  12. O. Ambacher, B. Foutz, J. Smart, J. R. Shealy, N. G. Weimann, K. Chu, M. Murphy, A. J. Sierakowski, W. J. Schaff, and L. F. Eastman, "Two dimensional electron gases induced by spontaneous and piezoelectric polarization in undoped and doped AlGaN/GaN heterostructures", J. Appl. Phys. 87, 334 January 2000. https://doi.org/10.1063/1.371866
  13. O. Ambacher, J. Smart, J. R. Shealy, N. G. Weimann, K. Chu, M. Murphy, W. J. Schaff, and L. F. Eastman, "Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- And Ga-face AIGaN/GaN heterostructures", J. Appl. Phys. 85, 3222-3223, March 1999. https://doi.org/10.1063/1.369664
  14. M.A. Mastroa, J.R. LaRocheb, N.D. Bassima and C.R. Eddy, Jr. "Simulation on the effect of non-uniform strain from the passivation layer on AlGaN/GaN HEMT", Microelectronics Journal. 36, pp. 705-711, August 2005. https://doi.org/10.1016/j.mejo.2005.02.121