Sputter deposition of yttria-stabilized zirconia onto a porous Au substrate

Process issues key to thin-film/solid--oxide fuel cells include the deposition of defect-free electrolyte layers on porous electrodes, gas transport through the porous conducting electrodes, and sufficient structural integrity for stack assembly and temperature cycling. This study addresses the method of electrolyte layer deposition. Our initial approach uses a porous metal substrate to permit measurement of the electrolyte performance as well as provide a pore size similar to conventional cermet electrodes. The sputter deposition of Au under controlled process parameters provides the porous substrate. An optimum choice for the electrolyte material is yttria-stabilized zirconia (YSZ). Our focus is to evaluate the process parameters of rf sputtering a YSZ target to densely coat the porous (Au) substrate. A high sputter gas pressure of Argon facilitates filling surface voids of the porous substrate leading to the formation of a defect-free layer of cubic YSZ as examined with electron microscopy techniques. copyright 1995 American Vacuum Society