Electron beam damaged high-T/sub c/ junctions-stability, reproducibility and scaling laws

The problems of stability and reproducibility of the electron beam irradiated high-T/sub c/ junctions have been studied. It is found that with a overdamage-anneal protocol that stable junctions can be obtained. While on chip uniformity can be very good (1%), the chip to chip reproducibility is not better than 20%. The annealing process allows us to vary T/sub c/ of the junctions over a wide range, making it possible to study the scaling behaviour of a single junction. We find that in these junctions I/sub c/R/sub n//spl prop/J/sub c//sup n/, with n=0.75-0.8 or, since the quasiparticle and Cooper-pair cross sections appear to be equivalent, I/sub c/R/sub n//spl prop//spl sigma//sub N//sup p/ where p=3.0-3.7.<
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