A process for the fabrication of high‐quality, all‐refractory Josephson junctions of the type Nb/SixNy/Nb is described in detail. The junctions have been fabricated using the selective niobium anodization process with a tunnel barrier consisting of an amorphous Si film converted to its nitride by the application of a rf plasma of nitrogen. An attractive feature of these junctions is their comparably low specific capacitanceC/A=3.9±0.1 &mgr;F/cm2(forJc=6 A/cm2). Junctions of this type having critical current densities up toJc=2000 A/cm2andVm=16 mV have been fabricated. Excellent magnetic field threshold curves have also been observed for these junctions, indicating that the critical current density is very uniform.