Plasma Deposited Low k SiCOH Films with Improved Properties Using Nano Imbedded Layers Insertion

Integration and development of Cu BEOL with PECVD low-K dielectrics with k ~ 2.8 and -3.0 has been reported by our group [1-2, 8] and a number of institutions for the 130, 90 and 65 nm generations [3-7], and has become the predominant path chosen by the industry. In effort to lower the SiCOH ILD dielectric constant, voids had been introduced into the SiCOH film making it become highly porous . As the result, the material also becomes more susceptible to cracking during thick Cu/ILD fabrication. In this paper, we report a simple method to form imbedded nano thickness layer film to enhance the cracking resistance for both plasma deposited SiCOH with low dielectric constants (k~ 2.8) and 2.2 (k~2.2 film has about 30 % porosity). The SiCOH films with k ~2.8 reported here were engineered for the highest levels of mechanical and electrical properties and reliability with simple plasma CVD process chemistry with enhanced bonding structure. This paper focuses on the formation of the imbedded nano layer during the film’s deposition and characterization of the high mechanical properties k film with dielectric constant in the range of 2.8 using simple and low cost organosilicon precursor and oxidant. The same evaluation was implemented with the highly porous SiCOH film with k~2.2.

By: Son Nguyen, E. Liniger, B. Herbst, K. Malone, N. Klymko, S. Cohen, E. Simonyi, S. Lane, C. Dziobkowski, M. Lane, A. Grill, D. Restaino, S. Gates, D. Edelstein, Tom Ivers

Published in: RC24375 in 2007

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