Share Email Print

Proceedings Paper

In-line and nondestructive analysis of selectively grown epitaxial Si1-xGex and Si/ Si1-xGex layers by spectroscopic ellipsometery and comparison with other established techniques
Author(s): Roger Loo; Matty Caymax; Guillaume Blavier; Stephanie Kremer
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

The increased interest in epitaxial Si1-xGex/Si heterostructures for device applications requires very good control of layer thickness and composition. Unfortunately, most of the well-developed characterization methods such as Rutherfored Backscattering Spectroscopy, Secondary Ion Mass Spectroscopy, and Photoluminescence measurements are unsuitable as production measurement tools. On the contrary, Spectroscopic Ellipsometry allows a fast, in-line and non- destructive analysis, including wafer mapping facilities. This paper demonstrates the suitability of Spectroscopic Ellipsometry for the determination of both Ge content and layer thickness of epitaxial Si1-xGex for Ge contents between 1 and 36%. By describing the optical dispersion by means of the harmonic oscillator model, we obtained a clear correlation between the Ge content and En(1), the resonant energy of the first oscillator, and nmax, the peak value of the real part of the refractive index. The small spot (28 X 14 micrometer2) size allows to analyze Si1-xGex layers grown in an isolation structure. The small window size prevents Rutherford Backscattering Spectroscopy measurements. Spectroscopic Ellipsometry allowed the fine tuning of selective and non-selective epitaxial growth processes with regard to growth rate, Ge incorporation and wafer uniformity. Furthermore, Spectroscopic Ellipsometry might be capable to extract separate thicknesses of more complex structures. This was successfully applied on Si capped Si1-xGex layers.

Paper Details

Date Published: 23 April 2001
PDF: 10 pages
Proc. SPIE 4406, In-Line Characterization, Yield, Reliability, and Failure Analysis in Microelectronic Manufacturing II, (23 April 2001); doi: 10.1117/12.425283
Show Author Affiliations
Roger Loo, IMEC (Belgium)
Matty Caymax, IMEC (Belgium)
Guillaume Blavier, KLA-Tencor Corp. (France)
Stephanie Kremer, KLA-Tencor Corp. (France)

Published in SPIE Proceedings Vol. 4406:
In-Line Characterization, Yield, Reliability, and Failure Analysis in Microelectronic Manufacturing II
Gudrun Kissinger; Larg H. Weiland, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?