Nb multilayer planarization technology for a subnanosecond Josephson 1K-bit RAM

Author

Nagasawa, S. ; Wada, Y. ; Tsuge, H. ; Hidaka, M. ; Ishida, I. ; Tahara, S.

Author_Institution

NEC Corp., Kawasaki, Japan

Volume

25

Issue

2

fYear

1989

fDate

3/1/1989 12:00:00 AM

Firstpage

777

Lastpage

782

Abstract

A fabrication process for a Josephson 1-kb RAM (random access memory) has been developed using a Nb multilayer planarization technology. The technology consists of an etchback technique using 2000-molecular-weight polystyrene and SiO₂ for the junction layer and wiring layers, and a tapered edge etching technique for contact between individual wiring layers. Excellent planarity, wherein level differences in all step areas were reduced to less than 1/20th of their original values, was achieved. Appropriate RAM operation with 570-ps minimum access time and 13-mW power dissipation, were confirmed

Keywords

integrated circuit technology; integrated memory circuits; niobium; random-access storage; superconducting junction devices; superconducting memory circuits; 1 kbit; 13 mW; 570 ps; Nb; Nb multilayer planarization technology; RAM operation; SiO₂; access time; etchback technique; fabrication process; junction layer; level differences; planarity; polystyrene; power dissipation; random access memory; subnanosecond Josephson 1K-bit RAM; tapered edge etching technique; wiring layers; Etching; Fabrication; Insulation; Niobium; Nonhomogeneous media; Planarization; Read-write memory; Resistors; Sputtering; Wiring;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.92403

Filename

92403