MOS characteristics of Ta-Mo gate electrode with $ZrO_2$

$ZrO_2$ 절연막을 이용한 Ta-Mo 합금 MOS 게이트 전극의 특성

  • An, Jae-Hong (Hankook Aviation University, Department of Electronic Engineering) ;
  • Kim, Bo-Ra (Hankook Aviation University, Department of Electronic Engineering) ;
  • Lee, Joung-Min (Hankook Aviation University, Department of Electronic Engineering) ;
  • Hong, Shin-Nam (Hankook Aviation University, Department of Electronic Engineering)
  • 안재홍 (한국항공대학교 전자공학과) ;
  • 김보라 (한국항공대학교 전자공학과) ;
  • 이정민 (한국항공대학교 전자공학과) ;
  • 홍신남 (한국항공대학교 전자공학과)
  • Published : 2005.07.07

Abstract

MOS capacitors were fabricated to study electrical and chemical properties of Ta-Mo metal alloy with $ZrO_2$. The work function of Ta-Mo alloy were varied from 4.1eV to 5.1eV by controlling the composition. When the atomic composition of Mo is 10%, good thermal stability up to $800^{\circ}C$ was observed and work function of MOS capacitor was 4.1eV, compatible for NMOS application. But pure Ta exhibited very poor thermal stability. After $600^{\circ}C$ annealing, equivalent oxide thickness of tantalum gate MOS capacitor was continuously decreased. Barrier heights of Ta-Mo alloy and pure metal that supported the work function values were calculated from Fowler-Nordheim analysis. As a result of these electrical?experiments, Ta-Mo metal alloy with $ZrO_2$ is excellent gate electrode for NMOS.

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