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Title: Effect of UV curing time on physical and electrical properties and reliability of low dielectric constant materials

Journal Article · · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films
DOI:https://doi.org/10.1116/1.4900854· OSTI ID:22318078
;  [1]; ; ;  [2]
  1. Department of Electrical Engineering, National Chi-Nan University, Nan-Tou, Taiwan, 545661 (China)
  2. Department of Materials Science and Engineering, National Chiao-Tung University, Hsin-Chu, 30050, Taiwan (China)

This study comprehensively investigates the effect of ultraviolet (UV) curing time on the physical, electrical, and reliability characteristics of porous low-k materials. Following UV irradiation for various periods, the depth profiles of the chemical composition in the low-k dielectrics were homogeneous. Initially, the UV curing process preferentially removed porogen-related CH{sub x} groups and then modified Si-CH{sub 3} and cage Si-O bonds to form network Si-O bonds. The lowest dielectric constant (k value) was thus obtained at a UV curing time of 300 s. Additionally, UV irradiation made porogen-based low-k materials hydrophobic and to an extent that increased with UV curing time. With a short curing time (<300 s), porogen was not completely removed and the residues degraded reliability performance. A long curing time (>300 s) was associated with improved mechanical strength, electrical performance, and reliability of the low-k materials, but none of these increased linearly with UV curing time. Therefore, UV curing is necessary, but the process time must be optimized for porous low-k materials on back-end of line integration in 45 nm or below technology nodes.

OSTI ID:
22318078
Journal Information:
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 32, Issue 6; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
Country of Publication:
United States
Language:
English