High-resistivity Zr resistors with Ti barrier layer for Nb Josephson circuits

Author

Shiota, T. ; Ohara, S. ; Imamura, T. ; Hasuo, S.

Author_Institution

Fujitsu Lab. Ltd., Atsugi, Japan

Volume

3

Issue

3

fYear

1993

Firstpage

3049

Lastpage

3053

Abstract

Zr resistors are applied to Josephson integrated circuits in place of Mo because a Zr thin film has about five times the resistivity of Mo. Zr resistors do not need to be protected during etching, unlike conventional Mo resistors, because Zr has much smaller etching rate than Nb. Zr resistors occupy only 25% of a unit cell area. Using Zr resistors reduces the area of the Josephson gate and allows increased circuit integration. Increased contact resistance between Zr and Nb films after annealing at about 350 degrees C was found but suppressed with a Ti barrier. Resistors with a resistance variation throughout a wafer of within +or-2.8% were fabricated.<>

Keywords

annealing; contact resistance; etching; niobium; superconducting integrated circuits; thin film resistors; zirconium; 350 C; Josephson gate; Josephson integrated circuits; Mo resistors; Nb Josephson circuits; Nb-Ti-Zr; Ti barrier layer; Zr resistors; annealing; contact resistance; etching rate; resistivity; wafer; Argon; Circuits; Conductivity; Electrical resistance measurement; Etching; Niobium; Protection; Resistors; Semiconductor films; Zirconium;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.234840

Filename

234840