Our studies on the effect of process variables on the electrical properties of Josephson tunnel junctions were directed toward optimization of the process for cryogenic memory applications, for which special importance is placed on the dc Josephson current density j1, its stability and reproducibility, and the junction quality. Variables studied included rf voltage, oxygen plasma pressure, the presence of oxygen during deposition of the counter electrode, the Composition and surface state of the base electrode, junction geometry, radial position on the wafer, and storage and annealing conditions. Various process adjustments were made in order to obtain acceptable device characteristics. For example, good tunnel characteristics could be obtained using Pb-Au-In alloys if In concentrations >8 wt% (for a fixed 3% Au concentration) were used in the base electrode. High pressure and low rf voltage during oxidation were preferable, since these conditions led to low annealing factors. We were also able to adjust j1, locally by irradiation with high-energy (>5 keV) electrons.