Title :
Fundamental understanding of porous low-k dielectric breakdown
Author :
Lee, Shou-Chung ; Oates, A.S. ; Chang, Kow-Ming
Author_Institution :
Taiwan Semicond. Manuf. Co., Hsinchu, Taiwan
Abstract :
We investigate the impact of porosity on the reliability of low-k dielectrics. We show that electric field enhancement around pores occurs and is significantly increased by Cu interaction, suggesting a new potential mechanism for breakdown of dielectrics at stress conditions. We develop of an analytic model to predict failure distribution parameters as a function of porosity and show that the model is in good agreement with measurements for porosity in the range of 5% to 40%. We explain why the field acceleration factor gamma is a constant for all silica-based material according to percolation theory. We propose that the percolation path difference between high field and low field would make the field dependence on failure time become non-linear.
Keywords :
copper; electric breakdown; failure analysis; low-k dielectric thin films; percolation; porous materials; reliability; Cu; failure distribution parameters; field acceleration factor; nonlinear failure time; percolation theory; porous low-k dielectric breakdown reliability; silica-based material; stress condition; Cathodes; Copper; Dielectric breakdown; Dielectric constant; Failure analysis; Integrated circuit interconnections; Physics; Predictive models; Semiconductor device manufacture; Stress;
Conference_Titel :
Reliability Physics Symposium, 2009 IEEE International
Conference_Location :
Montreal, QC
Print_ISBN :
978-1-4244-2888-5
Electronic_ISBN :
1541-7026
DOI :
10.1109/IRPS.2009.5173300