Optical Property Changes in Low-k Films upon Ultraviolet-Assisted Curing
Authors | |
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Year of publication | 2008 |
Type | Article in Periodical |
Magazine / Source | Journal of the electrochemical society |
MU Faculty or unit | |
Citation | |
Field | Solid matter physics and magnetism |
Keywords | low-k; ellipsometry; UV-cure |
Description | Ultraviolet-assisted curing (UV curing) has been recently applied to enhance the mechanical properties of low-k films. Knowledge about which ultraviolet energies are most effective is still limited and the consequences of applying the UV-curing process to integrated stacks in on-chip interconnects unknown. To clarify these open questions we investigated the optical properties of a SiCOH low-k layer by purged ultraviolet spectroscopic ellipsometry in the energy region 2-9 eV. The complex refractive index of the low-k film shows an absorption edge with a superimposed absorption band at 6.4 eV that vanishes upon ultraviolet-assisted curing. Comparison with Fourier transform infrared transmission demonstrates that the absorption at 6.4 eV must be attributed to the organic porogens, which have also influences on the absorption edge. |
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