A method for forming a PECVD deposited ashable hardmask (AHM) with less than 30% H content at a process temperature below 500.degree. C., e.g., about 400.degree. C. produces low H content hard masks having the property of high selectivity of the hard mask film to the underlying layers for successful integration of the film, and are suitable for use with 193 nm generation and below lithography schemes wherein high selectivity of the hard mask to the underlying layers is required. The low temperature, low H films are produced by use of a pulsed film hydrocarbon precursor plasma treatment that reduces the amount of hydrogen incorporated in the film and therefore drives down the etch rate of the hard mask thus increasing the selectivity. The lower temperature process also allows reduction of the overall thermal budget for a wafer.