Investigations into Composition and Structure of DBD-Deposited Amino Group Containing Polymer Layers

Amino group containing films of maximum 30 nm thickness were deposited on gold-coated wafers using atmospheric pressure dielectric barrier discharges (DBD) and process gases consisting of aminopropyl-trimethoxysilane (APTMS) as precursor in combination with various carrier gases including nitrogen, helium, argon, or a mixture of ammonia and nitrogen. With CD-XPS a concentration [NH2]/[C] of up to almost 6% was found. Storage of the films in air for four weeks generally led to a considerable reduction of the primary amino group concentration; however, in the case of the films produced using ammonia in nitrogen as carrier gas the concentration remained stable at just under 4%. Oxidation products according to XPS and IR data include amides and nitriles though imines may also be present.