Epitaxial growth and structure of the high-k dielectric Pr2O3 on Si(001) and Si(111)
Abstract
Keeping the capacitance of CMOS devices constant while shrinking further the gate dimensions requires intolerably thin SiO2 layers for next generation devices. Thus, replacing SiO2 with a material with larger static permittivity k and matching properties is at present a very urgent task. Among others, the sesquioxide Pr2O3 is discussed as a possible candidate material. We deposited ultra thin films of Pr2O3 by e-beam evaporationon atomically clean (001) and (111) surfaces. We studied the growth from the very early stages using low energy electron diffraction, scanning tunneling microscopy, Auger electron spectroscopy, grazing incidence X-ray diffraction, X-ray reflectivity and X-ray photoelectron spectroscopy. On Si(111), Pr2O3 grows pseudomorphically in the hexagonal phase. On Si(001) surface, a 0.6 nm thick layer of cubic Pr2O3 grows followed by the formation of a silicate layer on top. Growth under 10-8 mbar O2 atmosphere is needed in order to prevent Pr-silicide formation.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2006
- Bibcode:
- 2006APS..MARR12014Z