Journal of the Korea Institute of Information and Communication Engineering (한국정보통신학회논문지)

The Korea Institute of Information and Commucation Engineering (한국정보통신학회)
권호 표지
DOI QR코드

DOI QR Code

Analysis for Gate Oxide Dependent Subthreshold Swing of Asymmetric Double Gate MOSFET

비대칭 DGMOSFET의 문턱전압이하 스윙에 대한 게이트 산화막 의존성 분석

  • Jung, Hakkee (Department of Electronic Engineering, Kunsan National University)
  • Received : 2013.11.15
  • Accepted : 2013.12.24
  • Published : 2014.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

This paper has presented the change of subthreshold swings for gate oxide thickness of asymmetric double gate(DG) MOSFET, and solved Poisson equation to obtain the analytical solution of potential distribution. The Gaussian function as doping distribution is used to approch experimental results. The symmetric DGMOSFET is three terminal device. Meanwhile the asymmetric DGMOSFET is four terminal device and can separately determine the bias voltage and oxide thickness for top and bottom gates. As a result to observe the subthreshold swings for the change of top and bottom gate oxide thickness, we know the subthreshold swings are greatly changed for gate oxide thickness. Especially we know the subthreshold swings are increasing with the increase of top and bottom gate oxide thickness, and top gate oxide thickness greatly influences subthreshold swings.

비대칭 이중게이트(double gate; DG) MOSFET의 문턱전압이하 스윙의 게이트 산화막 두께에 대한 변화를 고찰하였으며 이를 위하여 포아송방정식의 해석학적 전위분포를 구하였다. 특히 포아송방정식을 풀 때 도핑분포함수에 가우시안 함수를 적용함으로써 보다 실험값에 가깝게 해석하였다. 비대칭 DGMOSFET 소자는 대칭적 구조를 갖는 DGMOSFET와 달리 4단자 소자로서 상단과 하단의 게이트 산화막 두께 및 인가전압을 달리 설정할 수 있다. 비대칭 DGMOSFET의 문턱전압이하 스윙을 상 하단 게이트 산화막 두께 변화에 따라 관찰한 결과, 게이트 산화막 두께에 따라 문턱전압이하 스윙은 크게 변화하는 것을 알 수 있었다. 특히 상 하단 게이트 산화막 두께가 증가할 때 문턱전압이하 스윙 값도 증가하였으며 상단 게이트 산화막 두께의 변화가 문턱전압이하 스윙 값에 더욱 큰 영향을 미치고 있다는 것을 알 수 있었다.

Keywords

References

  1. N.Chevillon, J.Sallese, C.Lallement, F.Pregaldiny, M.Madec and J.Aghassi,"Generalization of the Concept of Equivalent Thickness and Capacitance to Multigate MOSFETs Modeling," IEEE Electron Devices, vol.59, no.1, pp.60-71, 2012. https://doi.org/10.1109/TED.2011.2171347
  2. M.Schwarz, T.Holtij, A.Kloes and B.Iniguez,"2D Analytical Framework for Compact Modeling of the Electrostatics in Undoped DG MOSFETs," 18th International conference Mixed Design of Integrated Circuits and Systems, Poland, 16-18th June, pp.405-410, 2011.
  3. P.K. Tiwari, S. Kumar, S. Mittal, V. Srivastava, U. Pandey and S. Jit, "A 2D Analytical Model of the Channel Potential and Threshold Voltage of Double-Gate(DG) MOSFETs with Vertical Gaussian Doping Profile," India, 14-16th Mar., IMPACT-2009, pp.52-55, 2009.
  4. Z.Ding, G.Hu, J.Gu, R.Liu, L.Wang and T.Tang,"An analytical model for channel potential and subthreshold swing of the symmetric and asymmetric double-gate MOSFETs," Microelectronics J., vol.42, pp.515-519, 2011. https://doi.org/10.1016/j.mejo.2010.11.002
  5. R.Vaddi, R.P.Agarwal, S.Dasgupta, "Analytical modeling of subthreshold current and subthreshold swing of an underlap DGMOSFET with tied- independent gate and symmetricasymmetric options," Microelectronics J., vol.42, pp.798- 807, 2011. https://doi.org/10.1016/j.mejo.2011.01.004
  6. D.S.Havaldar, G.Katti, N.DasGupta and A.DasGupta, "Subthreshold Current Model of FinFETs Based on Analytical Solution of 3-D Poisson's Equation," IEEE Trans. Electron Devices, vol. 53, no.4, 2006.
  7. H.K.Jung and D.S.Cheong,"Analysis for Relation of Oxide Thickness and Subthreshold Swing of Asymmetric Double Gate MOSFET," Conference on Information and Communication Eng., vol.17, no.2, pp.698-701, 2013.