Gate Direct Tunneling Current in Uniaxially Compressive Strained nMOSFETs: A Sensitive Measure of Electron Piezo Effective Mass

Wei-Han Lee, Ming-Jer Chen

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Currently, both the band-structure calculation and the mobility measurement are used to assess the electron piezo-effective-mass coefficients in strained nMOSFETs. In this paper, we present a new experimental method through a fitting of the strain-altered electron gate direct tunneling current. The core of this method lies in the sensitivity of the direct tunneling to the position of the subband level in the presence of the electron piezo-effective-mass coefficients. First, a correction-coefficient generating expression is systematically constructed to compensate for the error in the subband levels due to the use of a triangular potential approximation. Then, with the known deformation potential constants and uniaxially compressive stress in the channel as inputs, a strain quantum simulator is carried out. The resulting gate direct tunneling current is used to fit experimental data, thus leading to the values of the piezo-effective-mass coefficients associated with the twofold and fourfold valleys. The comparison of the extracted piezo-effective-mass coefficients to those published in the literature is made.
Original languageEnglish
Pages (from-to)39-45
Number of pages7
JournalIEEE Transactions on Electron Devices
DOIs
StatePublished - Jan 2011

Keywords

  • Effective mass; mechanical stress; MOSFET; piezo; quantum confinement; tunneling; uniaxially compressive strain
  • BAND-STRUCTURE; SI; INVERSION; MOBILITY; SILICON; STRESS; MODEL; OXIDES Author Information

Fingerprint Dive into the research topics of 'Gate Direct Tunneling Current in Uniaxially Compressive Strained nMOSFETs: A Sensitive Measure of Electron Piezo Effective Mass'. Together they form a unique fingerprint.

  • Cite this