for use in wet etch processes during the production of semiconductor and mems devices are provided the layers include a primer layer a first protective layer and an optional second protective layer the primer layer preferably comprises an organo silane compound in a solvent system the first protective layer includes thermoplastic copolymers prepared from styrene acrylonitrile and optionally other addition polymerizable monomers such as acrylate monomers vinylbenzyl chloride and diesters of maleic acid or fumaric acid the second protective layer comprises a highly halogenated polymer such as a chlorinated polymer which may or may not be crosslinked upon heating application_number US 42812306 A description the following examples set forth preferred methods in accordance with the invention it is to be understood however that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention prior to applying the primer layer it is preferable to prepare the substrate by exposing it to brief from about 15 60 seconds oxygen plasma etching to clean and or chemically activate the substrate surface to improve bonding by the primer layer plasma bombardment with heavy ions such as argon can also be beneficial for improving bonding such processes are especially effective for improving the bonding of the protective coating system to silicon nitride preferred substrates for use in this process include those selected from the group consisting of si substrates sio 2 substrates si 3 n 4 substrates sio 2 on silicon substrates si 3 n 4 on silicon substrates glass substrates quartz substrates ceramic substrates semiconductor substrates and metal substrates the organosilane solution that makes up the primer layer is spin applied.