SiO2 aerogel has great potential as a promising intermetal dielectric with low dielectric constant due to its porous nature. Dry etching of porous SiO2 should be carefully investigated for its application as an intermetal dielectric. The etching behaviour of SiO2 aerogel with inductively coupled CHF3 plasma etching was investigated and compared with thermally grown SiO2. A basic three-dimensional network structure, composed of SiO2 particles and internal pores, was maintained on the etching process. From angle-resolved X-ray photoelectron spectroscopy analyses, it was revealed that the etching process occurred not only at the aerogel film surface but also at the large internal surface. However, the effective etch rate was slower, from the consideration of 70% film porosity, compared with thermally grown SiO2. This is related to the large content of C and H in the SiO2 aerogel film.
Bibliographical noteFunding Information:
This work was supported by the Ministry of Education through the Inter-University Semiconductor Research Center ( ISRC 96-E-1063) in Seoul National University.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry