Direct observation of electronic states in gate stack structures: XPS under device operation

Y. Yamashita, H. Yoshikawa, T. Chikyo, K. Kobayashi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

Although gate stack structures with high-k materials have been extensively investigated, there are some issues to be solved for the formation of high quality gate stack structures. In the present study, we employed hard x-ray photoelectron spectroscopy in operating devices. This method allows us to investigate bias dependent electronic states while keeping device structures intact. Using this method we have investigated electronic states and potential distribution in a Pt gate metal/high-k gate stack structure under device operation. We have found that a potential gradient was formed at the Pt/HfO 2 interface by analyzing the shifts of the core levels as a function of the applied bias voltage. Angle resolved photoelectron spectroscopy revealed that a SiO 2 layer was formed at the Pt/HfO 2 interface. The formation of the SiO 2 layer at the interface might concern the Fermi level pinning, which is observed in metal/high-k gate stack structures.

Original languageEnglish
Title of host publicationULSI Process Integration 7
Pages331-336
Number of pages6
Edition7
DOIs
Publication statusPublished - 2011 Dec 1
Event7th Symposium on ULSI Process Integration - 220th ECS Meeting - Boston, MA, United States
Duration: 2011 Oct 92011 Oct 14

Publication series

NameECS Transactions
Number7
Volume41
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Other

Other7th Symposium on ULSI Process Integration - 220th ECS Meeting
CountryUnited States
CityBoston, MA
Period11/10/911/10/14

ASJC Scopus subject areas

  • Engineering(all)

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