| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Thursday Sessions |
| Session EM-ThP |
| Session: | Electronic Materials and Processing Poster Session |
| Presenter: | X. Guo, University of Wisconsin-Madison |
| Authors: | X. Guo, University of Wisconsin-Madison J. Jakes, USDA Forest Service Forest Products Laboratory M. Nichols, University of Wisconsin-Madison S. Banna, Applied Materials Inc. Y. Nishi, Stanford University J.L. Shohet, University of Wisconsin-Madison |
| Correspondent: | Click to Email |
Water uptake in porous low-k dielectrics has become a significant challenge for both back-end-of-the-line integration and circuit reliability. The influence of absorbed water on the mechanical properties of PECVD organosilicate glasses (SiCOH) was investigated with nanoindentation. The roles of physisorbed (α-bonded)and chemisorbed (β-bonded) water were examined separately through annealing at different temperatures. Nanoindentation measurements were made on dehydrated organosilicate glass (SiCOH) during exposure to different humidity conditions. The indentation results at shallow depth show that for as-deposited SiCOH, the elastic modulus and hardness were all intimately linked to the concentration of the absorbed water in the dielectric bulk and qualitatively held the same evolution mechanism with in-diffused water concentration. After annealing, the water-concentration-related film mechanical property changes were shown to be reversible. UV curing of SiCOH was shown to lower water-induced mechanical property variation effectively by depopulating the hydrophilic chemical groups in SiCOH. A high-load indentation test shows that in-diffusion of water at the film/substrate interface can degrade the hardness of a SiCOH/Si film stack significantly, while showing less effect on the elastic modulus.
This work was supported by the Semiconductor Research Corporation under Contract 2012-KJ-2359 and by the National Science Foundation under Grant CBET-1066231.