Patent ID: 6194353
Filing Date: 2001-02-27
Classification: C23C,C30B,H01L,Y10S

Abstract:
A process for preparing a film formed of Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-.delta. oxide superconductor having a clean, crystalline and superconductive surface as grown on a substrate by MBE wherein said process comprises conducting said MBE in an MBE apparatus having a vacuum chamber in which pressure around the substrate is elevated while maintaining lower pressure near an evaporation source, wherein said lower pressure is a pressure less than said pressure around the substrate, under a condition that the substrate is heated to a temperature of 650 to 730.degree. C. an oxidizing gas is locally supplied to the proximity of the substrate so that the pressure in the proximity of the substrate becomes 6.times.10.sup.-6 to 8.times.10.sup.-5 Torr at a background pressure of lower than 1.times.10.sup.-9 Torr and using metal yttrium, metal barium and metal copper as evaporation sources set to K cells, wherein a temperature of the K cell of the metal yttrium is in the range of 1150 to 1350.degree. C., a temperature of the K cell of the metal barium is in the range of 570 to 640.degree. C., and a temperature of the K cell of the metal copper is in the range of 950 to 1090.degree. C., wherein said thin film is deposited at a deposition rate in the range of 0.5 to 2 nanometers/minute.