with a 0 2 0 45 u03bcm polypropylene filter composition h was prepared by dissolving 10 g of chlorinated pvc temprite 674x571 from noven inc in 90 g of cyclohexanone followed by filtering with a 0 2 0 45 u03bcm polypropylene filter a silicon silicon nitride or silicon nitride wafer with aluminum deposited at the central area was mounted on a spin coater and centered properly under conditions of a spin acceleration rate of 20 000 rpm 2 a spin speed of 2 500 rpm and a duration of 90 seconds the wafer was first washed with acetone for about 20 seconds to remove any possible contaminants and then an aliquot of 5 to 10 ml of the primer was dispensed onto the wafer after spinning for about another 40 to 60 seconds a uniform primer layer was obtained on top of the wafer subsequently the primed wafer was baked on a hotplate at 100 130 u00b0 c for 1 minute to promote chemical bonding between the substrate and the primer as well as partial vulcanization of the primer after the primed wafer cooled to room temperature a layer of the particular coating composition e g composition a was spin applied and then baked on a hotplate sequentially at 100 u00b0 c for 2 minutes 130 u00b0 c for 1 minute and.