To fabricate a low-k-value interconnect film with a sufficient modulus and high thermal stability, we investigated using an admixture precursor (dimethoxytetramethyldisiloxane and methyltrimethoxysilane) in a neutral beam enhanced chemical vapor deposition (NBECVD) process. It was possible to precisely control the film properties because the NBECVD process can precisely control the molecular level structures, such as the composition ratio of linear and network/cage Si-O structures, by changing the precursor mixture ratio. Experimental results showed that the SiOCH low-k film had a super-low k-value of less than 2.1 and a sufficient modulus of more than 6 GPa. A high thermal stability was also achieved by stacking a 20-nm-thick methyltrimethoxysilane (MTMOS) cap layer on the NBECVD super-low-k film.
ASJC Scopus subject areas
- Physics and Astronomy(all)