科研之友
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摘要
Aromatic polyimide (API) thin films were deposited onto silicon wafers with microscopic-scale trenches (width: 5 mu m, depth: 30 mu m) using supercritical carbon dioxide at deposition temperatures that ranged from 150 to 230 degrees C and at a constant deposition time of 90 min. Moreover, the relationship between deposition time and film thickness was also investigated for durations that ranged from 30 to 180 min at a deposition temperature of 200 degrees C. We used 4,4 '-diaminodiphenyl ether and pyromellitic dianhydride of Kapton-type polyimide API monomers. Although the morphologies of the API films deposited on the outside surfaces of the trenches depended on the distance from the supply outlets of the monomers, the API thin films were deposited onto the surfaces of the walls of the trenches with an approximately equal thickness from the outer surface position to the bottom position regardless of the distance from the supply outlets. However, the film thickness on the walls of the trenches depended on the distance from the supply outlets, because the trenches near the supply outlets were likely to be blocked by the masses of APIs during deposition. The film deposited at 230 degrees C was much smoother than that deposited at either 150 or 200 degrees C, which could have been caused by the differences in imidization rates and the amounts of PAA entering into the trenches based on the differences in the deposition temperatures although the film thickness showed no significant temperature dependency in the experimental conditions. The film thickness increased with increases in deposition time on the walls of the trenches in positions where no masses of APIs were found on the outer surface.
- 出版日期2015-5
