Chemical vapor deposition (CVD) is a critical processing technology in the semiconductor industry, and over the past several years, significant strides have been made in developing CVD technologies for the controlled synthesis of compositionally well-defined polymer thin films. CVD of polymers is attractive because it combines synthesis and thin film processing into a single step, while eliminating the use of solvent required in conventional solution-based processing. An important variant of polymer CVD is initiated chemical vapor deposition as it provides exquisite control over polymer chemistry and film morphology by essentially executing a heterogeneous free radical polymerization. Inspired by this iCVD approach, a novel polymer CVD approach has been developed based on classical cationic chain polymerization. This approach has been term catCVD. In catCVD, coinitiation with a Lewis acid and a proton-donor is used to protonate vinyl bonds in surface-adsorbed monomer molecules, leading to the formation of carbenium ions. The thermodynamics and kinetics of catCVD are highly favorable, and the reaction proceeds spontaneously, eliminating the need for heated filaments as in iCVD or any other energy input. In initial proof-of-concept experiments, polystyrene films were synthesized by catCVD and iCVD. Fourier-transform infrared spectroscopy (FTIR) showed that the film compositions are nearly identical, while real-time interferometry showed that the deposition rate of catCVD enhanced almost 50X relative to iCVD. The kinetics of catCVD were further analyzed to determine the functional dependence of the polymerization rate expression on deposition parameters, including precursor surface concentrations and substrate temperatures. It was shown that the rate of propagation is second order with respect to the monomer, which is in agreement with the accepted rate law for solution-based cationic polymerization. Size exclusion chromatography (SEC) of the deposited polymer films showed that polymer MW is invariant with respect to film thickness, indicating that the lifetime of the extending polymer chains is orders of magnitude shorter than the deposition time. We conclude that polymer initiation and termination are occurring continuously throughout the deposition process. Experiments are currently being executed to determine the activation energy for the polymerization rate constant. A comprehensive study of the polymer composition and film structure using various analytical techniques, including ellipsometry, x-ray photoelectron spectroscopy, and scanning electron microscopy will also be presented.