Air-gap sacrificial materials by initiated chemical vapor deposition

P(neopentyl methacrylate-co-ethylene glycol dimethacrylate) copolymer, abbreviated as P(npMAco-EGDA), was selected as the potential air-gap sacrificial material among possible combination of twenty monomers and four crosslinkers. P(npMA-co-EGDA) was deposited onto substrates using initiated chemical vapor deposition (iCVD) technique. Spectroscopic data showed the effective incorporation of both components in the copolymer and the integrity of repeating units were retained. The onset temperature of decomposition of P(npMA-co-EGDA) copolymer could be tuned between 290-3500C by varying the composition of the copolymer. The removal rate of polymer was calculated based on interferometry signal-time curve. The activation energy was determined by fitting the rate of decomposition with logistic model and found to be 162.7+8kJ/mole, which was similar to published data. Flash pyrolysis gas chromatography mass spectroscopy analysis showed that the products of thermal decomposition are monomers, rearranged small molecules and low oligomers. The modulus and the hardness were in the range of 3.9 to 5.5 GPa and 0.38 to 0.75 GPa, respectively, and were higher than those of linear poly(methyl methacrylate) (PMMA). Air-gap structures were constructed in the following scheme: P(npMA-co-EGDA) was deposited on the substrate by iCVD, followed by spincasting PMMA electron beam resist and scanning electron beam lithography to implement patterns on the resist. Reactive ion etching (RIE) was then applied to simultaneously etch the PMMA resist and P(npMA-co-EGDA) sacrificial material away in a controlled manner, leaving the patterned sacrificial material on the substrate.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Lee, Long Hua

Advisor dc:contributor.advisor

• Karen K. Gleason.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/44292

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/44292