Niobium‐stress influence on Nb/Al‐oxide/Nb trilayer Josephson‐junction characteristics is studied. Different junction fabrication techniques are examined such as conventional etching and new lift‐off processes. Nb‐film stress, relaxed during trilayer etching, can deteriorate junction quality in etching‐processed junctions smaller than a few micrometers square. Such deterioration does not occur in lift‐off processed junctions even when they are 1 &mgr;m square because stress relaxation occurs during trilayer deposition through lift‐off stencils. This new all‐Nb Josephson‐junction fabrication technique produces high‐quality junctions withRsg/Rnn=24 (RsgandRnnare tunnel resistances at 2 and 4 mV, respectively) and a current uniformity of 1.5% for 100 1‐&mgr;m‐square junctions connected in series.