JOSEPHSON ELEMENT AND MANUFACTURE THEREOF

PURPOSE:To obtain a barrier layer which has a thickness of the order of nm and is high is adhesion strength and small is number of pinholes by a method wherein a chemical adsorbing film is used as the barrier layer which isolates an upper electrode from a lower electrode. CONSTITUTION:A lower electrode 2 of a superconductor is provided on a substrate 1, hydrophilic groups are formed thereon, chlorosilane adsorbent gas which contains straight carbon chain provided with chlorine-silicon chemical bond (-SiClX3-n group, n=2 or 3, X is functional group) at its one end is made to react thereon to enable chemical adsorbing film precursor to be adsorbed, and then the absorbed chemical adsorbing film precursor is formed into an adsorbing film 3 (barrier layer) of -Si(O-)3 through the reaction of hydrolysis, and dehydration condensation. It is preferable that the chemical adsorption process is carried out at least twice or more. An upper electrode of superconductor is formed on the surface of the barrier layer, and thus a Josephson element 5 can be obtained.