Fabrication of Nb/AlO/sub x//Nb tunnel junctions using focused ion beam implanted Nb patterning (FINP) technique

Author

Akaike, H. ; Fujimaki, A. ; Takai, Y. ; Hayakawa, H.

Author_Institution

Dept. of Electron., Nagoya Univ., Japan

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

2187

Lastpage

2190

Abstract

The focused ion beam implanted Nb patterning (FINP) technique was applied to the fabrication process of Nb/AlO/sub x//Nb tunnel junctions. The essence of this technique is that Ga-ion-implanted layers in Nb films serve as a masking layer during reactive ion etching in CF/sub 4/ plasma. Uniform and reproducible patterns of 0.3*0.3 mu m/sup 2/ have been formed by this technique. The tunnel junction fabricated with a 60-keV ion beam had the quality parameter Vm of 48 mV, which indicates no degradation of junction characteristics by focused ion beam irradiation. The authors also investigated the CF/sub 4/ plasma etching characteristics of Ga-ion-implanted Nb films and found that an improvement in the characteristics is achieved by lowering beam energy and raising CF/sub 4/ gas pressure.<>

Keywords

Josephson effect; aluminium compounds; focused ion beam technology; ion beam lithography; ion implantation; niobium; sputter etching; superconducting junction devices; type II superconductors; 60 keV; Ga ion implantation; Nb-AlO/sub x/-Nb junctions; Nb:Ga films; fabrication; focused ion beam implanted Nb patterning; masking layer; plasma etching; reactive ion etching; reproducible patterns; superconducting tunnel junctions; Etching; Fabrication; Integrated circuit technology; Ion beams; Lithography; Niobium; Particle beams; Plasma applications; Plasma properties; Resists;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.233937

Filename

233937