Margins and yields of SFQ circuits in HTS materials

Author

Miller, D.L. ; Przybysz, J.X. ; Kang, J.H.

Author_Institution

Westinghouse Sci. & Technol. Center, Pittsburgh, PA, USA

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

2728

Lastpage

2731

Abstract

An analytical model has been developed to project the yield of superconductive integrated circuit chips as a function of circuit operating margins, fabrication process control, and component count. For Gaussian distributed deviations of critical component values from design specifications, chip yield was a highly nonlinear (threshold) function of the ratio of circuit margin to process standard deviation. Computer simulations of single-flux-quantum (SFQ) logic gates with model high-temperature superconductor (HTS) superconductor-normal-metal-superconductor (SNS) junctions operating at GHz clock rates showed at least 50-70% of the margins of similar Nb-Al/sub 2/O/sub 3/-Nb based circuits. Margins and maximum clock rate improved as I/sub c/R/sub n/ (critical-current-normal-resistance product) was increased from 200 to 500 mV.<>

Keywords

Josephson effect; high-temperature superconductors; modelling; superconducting junction devices; superconducting logic circuits; Gaussian distributed deviations; HTSC; Nb-Al/sub 2/O/sub 3/-Nb based circuits; SFQ circuits; SNS junctions; analytical model; chip yield; circuit operating margins; component count; computer simulation; fabrication process control; gigahertz clock rates; high-temperature superconductor; logic gates; single-flux-quantum; superconductive integrated circuit chips; superconductor-normal-metal-superconductor; yield analysis; Analytical models; Clocks; Fabrication; High temperature superconductors; Integrated circuit modeling; Integrated circuit yield; Process control; Superconducting integrated circuits; Superconducting materials; Superconductivity;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.233991

Filename

233991