In:
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, American Vacuum Society, Vol. 36, No. 6 ( 2018-11-01)
Abstract:
Perfluorocarbon gases are commonly used for nanoscale etching in semiconductor processing; however, they have the disadvantages of a long lifetime and inducing global warming effects when released into the atmosphere. In this study, the SiO2 etch characteristics and global warming effects of C3F6O gas chemistry, which has a low global warming potential, were compared with those of C4F8 chemistry, which is commonly used in semiconductor processing. Using Ar/C3F6O, the SiO2 etch rate was higher and the etch selectivity of SiO2 over the amorphous carbon hardmask layer was lower than the etch rate and etch selectivity using Ar/C4F8/O2, with all other etch conditions the same. Furthermore, using Ar/C3F6O exhibited more anisotropic SiO2 etch profiles by suppressing the bowing, narrowing, and necking effects compared to the etch profiles using Ar/C4F8/O2. The global warming effects were evaluated by calculating the million metric ton carbon equivalents (MMTCEs) from the volumetric concentrations of the emitted by-product species and process gases, and the results showed that, in the optimized conditions, Ar/C3F6O exhibited a lower environmental impact with an MMTCE of & lt;24% than that of Ar/C4F8/O2. Therefore, it is suggested that the Ar/C3F6O gas mixture is a potential replacement for Ar/C4F8/O2 because of its lower MMTCE and acceptable SiO2 etch characteristics.
Type of Medium:
Online Resource
ISSN:
0734-2101
,
1520-8559
Language:
English
Publisher:
American Vacuum Society
Publication Date:
2018
detail.hit.zdb_id:
1475424-1
detail.hit.zdb_id:
797704-9
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