Optical and Electrical Thickness Measurements of Alternate Gate Dielectrics: a Fundamental Difference

Published

February 1, 2001

Author(s)

Curt A. Richter, Nhan Van Nguyen, Evgeni Gusev, T H. Zabel, G A. Alers

Abstract

We will describe a fundamental difference between the interpretation of optical and electrical measurements of gate dielectric thickness. This difference has major ramifications on the characterization of, and metrology for, advanced, alternate gate dielectrics and gate dielectric stacks. The purpose of this presentation is to clear up possible misunderstandings that arise when comparing the thickness of gate dielectrics derived from optical and electrical measurements. Oxynitride data will be shown to illustrate the divergence between optical and electrical measurements of thickness for films with a permittivity near and slightly above that of SiO2. Experimental characterization of Ta2O5 dielectrics will be used to illustrate the complimentary nature of electrical and optical measurements.

Proceedings Title

Characterization and Metrology for ULSI Technology

Conference Dates

June 26-29, 2000

Conference Location

Gaithersburg, MD, USA

Pub Type

Conferences

Keywords

alternate gate dielectrics, ellipsometry, capacitance, effective oxide thickness

Citation

Richter, C. , Nguyen, N. , Gusev, E. , Zabel, T. and Alers, G. (2001), Optical and Electrical Thickness Measurements of Alternate Gate Dielectrics: a Fundamental Difference, Characterization and Metrology for ULSI Technology, Gaithersburg, MD, USA (Accessed October 12, 2025)