A PLANAR METHOD FOR PATTERNING OF HIGH-TEMPERATURE SUPERCONDUCTING FILMS AND MULTILAYERS

We present a novel technique for patterning high-temperature supercond ucting (HTS) film and multilayer device structures. In the process an impurity ion (e.g., Si) is implanted into HTS films through a photores ist mask. The impurity ions convert the irradiated portion of the film into an insulating form by chemical reaction between the ions and the oxygen in the film, without altering the overall crystalline structur e of the film. Removal of the photoresist results in a flat surface, w hich allows the epitaxial growth and implantation patterning of subseq uent films so that a complete multilayer device structure can be fabri cated. We show in detail the patterning process, as well as the proper ties of patterned and regrown films. Some simple device structures, su ch as a vertical contact and a crossover, are demonstrated.