Absiract-High quality reproducible junctions are mandatory in the construction of high-?', RF and DC SQUIDs using YBazCu307-, thin films. In this paper, we describe two methods used to produce step-edge junctions on MgO substrates suitable for SQUID devices. In both processes a titanium mask has been used to produce a straight, well defined step which assists, in minimizing the occurrence of multiple junctions. We describe two ionmilling processes which produce differently connected stepedge junctions as indicated by SEM micrographs, I-V and I,-B characteristics. Predictable relationships between the ratio of the film thickness t o step height and the junction critical-current density are demonstrated; these enable the creation of step-edge junctions with appropriate values of I, for particular SQUID designs.