Robert E Kampwirth

US Patent:

40640299, Dec 20, 1977

Filed:

Feb 8, 1977

Appl. No.:

5/766653

Inventors:

Cheng-Teh Wu - Hinsdale IL
Charles M. Falco - Woodridge IL
Robert T. Kampwirth - Darien IL

Assignee:

The United States of America as represented by the United States Energy
Research and Development Administration - Washington DC

International Classification:

C23C 1500
G01R 3302

US Classification:

204192S

Abstract:

An improved superconducting quantum interference device is made by sputtering a thin film of an alloy of three parts niobium to one part tin in a pattern comprising a closed loop with a narrow region, depositing a thin film of a radiation shield such as copper over the niobium-tin, scribing a narrow line in the copper over the narrow region, exposing the structure at the scribed line to radiation and removing the deposited copper.

US Patent:

42660084, May 5, 1981

Filed:

Nov 23, 1979

Appl. No.:

6/096859

Inventors:

Robert T. Kampwirth - Darien IL
Ivan K. Schuller - Woodridge IL
Charles M. Falco - Woodridge IL

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

H01L 3902

US Classification:

430318

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.