Bias Sputter Deposition of Dense Yttria‐Stabilized Zirconia Films on Porous Substrates

Abstract

We demonstrate that completely dense yttria‐stabilized zirconia (YSZ) electrolyte films <5 μm thick can be reactively sputter deposited onto porous (∼0.5 μ pore size) substrate/electrodes. The two key factors in achieving the fully dense films were porous substrate preparation and the use of substrate bias during YSZ film deposition. Increasing the negative dc substrate bias from 0 to 300 V produced increasingly dense and flat‐surfaced films: was chosen to yield high density without excessive film compressive stresses. Solid oxide fuel cells consisting of sputtered YSZ films and a Ni‐YSZ fuel electrode on LSM exhibited open‐circuit voltage values within 5% of the theoretical values for thicknesses down to 2 μm. Cells deposited with short‐circuited at thicknesses of 12 μm or less.