This work presents a detailed study of poly(neopentyl methacrylate-co-ethylene glycol diacrylate) [P(npMA-co-EGDA)] copolymer, which was selected for study from possible combination of 20 vinyl monomers and 4 divinyl crosslinkers as a candidate for sacrificial layer materials for the fabrication of air-gap structures. P(npMA-co-EGDA) was deposited onto substrates using an initiated chemical vapor deposition technique. Spectroscopic data showed the effective incorporation of both components in the copolymer and the retention of integrity of the repeating units. The onset temperature of decomposition of P(npMA-co-EGDA) and the removal percentage can be tuned between 290 and 350 S C and 93 and 98%, respectively, by varying the composition of the copolymer. The removal rate of copolymer was calculated based on interferometry signal-time curve. For all copolymers, the activation energy was determined to be 162.7 +/- 8 kJ mol(-1). The products of thermal decomposition were monomers, rearranged small molecules, and low oligomers. The modulus and the hardness were in the range of 3.9-5.5 and 0.38-0.75 GPa, respectively. Air-gap structures were constructed by patterning P(npMA-co-EGDA) with e-beam lithography, followed by capping with silica via plasma-enhanced chemical vapor deposition and thermal annealing at 36 degrees C. The feature size of a 70 nm air-gap structure was fabricated. (C) 2008 The Electrochemical Society.