Parylene-n (Poly-p-xylylene) (PA-n) [1-3] has a long history of use as a moisture barrier for printed circuit boards and hybrids. This paper evaluates this compound as a candidate vapor-depositable polymer interlayer dielectric for submicron integrated circuit technology due to its low dielectric constant, good step coverage, and high etch selectivity. To apply PA-n on high-density very large scale integrated circuits, its properties, such as deposition rate, deposition yield, and crystallinity, are investigated as a function of deposition pressure and annealing temperature. The deposition rate was found in the range of 2.66 Pa to 13.3 Pa to be a linearly increasing function of pressure. Good-quality films were obtained when pressure was controlled below 10.64 Pa. Cloudy films, however; were found at 13.3 Pa. The deposition rate could be as high as 3.33 x 10(-10) m s(-1) when deposited at 10.64 Pa. The plot of PA-n yield vs. pressure showed a constant plateau of 1 x 10(-4) m kg(-1) from 2.66 Pa to 10.64 Pa. The optimum deposition rate was hence obtained at 10.64 Pa without compromising the deposition yield. The crystallinity-associated properties examined were hardness, dielectric constant, and water permeability. A lower deposition pressure was observed to produce higher crystallinity that could be further enhanced by thermal annealing. A 5 x 10(-8) m hard surface layer was detected with hardness 3.5 GPa, that was 3 similar to 7 times larger than that of bulk hardness which was 0.4 similar to 0.7 GPa. The bulk hardness was found to increase as crystallinity increased. The dielectric constant tended to increase when the deposition pressure decreased. Furthermore, the dielectric constant was nearly constant when the polymer was heated up to temperatures as high as 698 K. This behavior, together with the formation of the hard layer and a higher crystallinity, was believed to result from the improved film organization of the deposited films. The competition between the film build-up in the surface region and the monomer diffusion into the bulk region (penetration) was theorized to be responsible for the film organization. The water permeability, which was measured to be as low as 1.2 x 10(-15) kg m(-1) s(-1) Pa-1 and was found to increase as the deposition pressure was increased, further strengthened the film organization claim.