Method for etching thin films of niobium and niobium-containing compounds for preparing superconductive circuits
US4266008A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1979 |
| Grant date | May 5, 1981 |
| Priority date | — |
| Expiry date | Nov 23, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N60/0156
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An improved method of preparing thin film superconducting electrical circuits of niobium or niobium compounds in which a thin film of the niobium or niobium compound is applied to a nonconductive substrate, and covered with a layer of photosensitive material. The sensitive material is in turn covered with a circuit pattern exposed and developed to form a mask of the circuit in photoresistive material on the surface of the film. The unmasked excess niobium film is removed by contacting the substrate with an aqueous etching solution of nitric acid, sulfuric acid and hydrogen fluoride, which will rapidly etch the niobium compound without undercutting the photoresist. A modification of the etching solution will permit thin films to be lifted from the substrate without further etching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.