Experimental results are presented which show that the nonideal nature of electrical characteristics derived from metal‐ZnO‐SiO2‐Si structures, structures of the type proposed in surface‐acoustic‐wave applications, is due in large part to a deterioration of the Si‐SiO2subsystem during the thin‐film ZnO deposition procedure. The thermally assisted breaking of surface‐state bonds and radiation damage are identified as the sources of the deterioration. Progress achieved to date in reducing the cited damage, including the use of radiation‐hardened SiO2films and a low‐temperature O2anneal, are also described and discussed.