C-axis transport properties and intrinsic Josephson effect in YBa/sub 2/Cu/sub 3/O/sub 7/-films

We have developed a standard photolithographic process to fabricate intrinsic Josephson effect (IJE) devices on the basis of thin films. In this way the dimensions of the structures could be reduced into the micron range which turned out to be essential to observe IJE signatures. Another key point was a reduction of the interlayer coupling in YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) which could be realized by removal of chain oxygen. The enhanced anisotropy led to RSJ-like current-voltage characteristics as well as microwave emission at 11 GHz and 24 GHz up to temperatures slightly below T/sub c/ demonstrating intrinsic Josephson coupling in YBCO for the first time.