Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-03T01:30:05.505Z Has data issue: false hasContentIssue false

Stress Development in Low Dielectric Constant Silica Films During Drying and Heating Process

Published online by Cambridge University Press:  10 February 2011

Mengcheng Lu
Affiliation:
Advanced Materials Laboratory, Sandia National Laboratories and the University of New Mexico/NSF Center for Micro-Engineering Materials, 1001 University Blvd. SE, Albuquerque, NM 87106, lumc @unm.edu
C. Jeffrey Brinker
Affiliation:
Advanced Materials Laboratory, Sandia National Laboratories and the University of New Mexico/NSF Center for Micro-Engineering Materials, 1001 University Blvd. SE, Albuquerque, NM 87106, lumc @unm.edu Sandia National Lab, Albuquerque, NM 87185, [email protected]
Get access

Abstract

Low dielectric constant silica films are made using a surfactant templated sol-gel process (K∼2.5) or an ambient temperature and pressure aerogel process (K∼1.5). This paper will present the in-situ measurement and analysis of stress development during the making of these films, from the onset of drying till the end of heating. The drying stress is measured by a cantilever beam technique; the thermal stress is measured by monitoring the wafer curvature using a laser deflection method. During the course of drying, the surfactant templated films experience a low drying stress due to the influence of the surfactant on surface tension and extent of siloxane condensation. The aerogel films first develop a biaxial tensile stress due to solidification and initial drying. At the final stage of drying where the drying stress vanishes, dilation of the film recreates the porosity of the wet gel state, reducing the residual stress to zero. For the surfactant templated films, very small residual tensile stress remains after the heat treatment is finished (∼30MPa). Aerogel film has almost no measurable stress developed in the calcination process. In situ spectroscopic ellipsometry analysis during drying and heating, and TGA/DTA are all used to help understand the stress development.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Carter, Kenneth R., Ultra Low k Workshop, ACS Division of Polymer Chemistry, Monterey, CA, Nov 14, (1999).Google Scholar
2. Brinker, C. J., Lu, Y., Sellinger, A, and Fan, H., Advanced Materials, 11(7), 579–585(1999).Google Scholar
3. Lu, Y., Ganguli, R., Drewien, C., Anderson, M., Brinker, C., Gong, W., Guo, Y., Soyez, H., Dunn, B., Huang, M., Zink, J., Nature, 389, 364(1997).Google Scholar
4. Sellinger, A., Weiss, P.M., Nguyen, A., Lu, Y., Assink, R. A., Gong, W., Brinker, C.J., Nature, 394, 256(1998).Google Scholar
5. Brinker, C. J., unpublished results.Google Scholar
6. Prakash, S. S., Brinker, C. J., Hurd, A. J. and Rao, S. M., Nature, 374, 439(1995).Google Scholar
7. Ting, C. H. and Seidel, T. E., Mat. Res. Soc. Symp. Proc. 381, edited by Lu, T.-M., Murarka, S. P., Kuan, T.-S., and Ting, C. H., p. 319(1995)Google Scholar
8. Lu, Mengcheng, unpublished results.Google Scholar
9. Parrill, T.M., J. Mater. Res., 9(3), 723730, (1994).Google Scholar
10. Sriram, C.S., Master Thesis, University of New Mexico, 1998.Google Scholar
11. Brinker, C.J., Scherer, G.W., Sol-Gel Science, The Physics and Chemistry of Sol-Gel Processing, (Academic Press Inc., 1990).Google Scholar