By Topic

Yield Evaluation of 10-kA/cm 2 Nb Multi-Layer Fabrication Process Using Conventional Superconducting RAMs

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

5 Author(s)

To achieve larger scale and higher speed single flux quantum (SFQ) circuits, we have been developing a 10-kA/cm2 Nb multi-layer fabrication process composed of more than six pla- narized Nb layers, an Nb/AlOx /Nb junction layer, a Mo resistor layer, and SiO2 insulator layers. To evaluate reliability of the fabrication process, we have designed superconducting random access memories (RAMs) with four different memory capacities: 256, IK, 4 K, and 16 K bits. Although the circuit configuration of these RAMs is almost the same as that of previously developed ones that have conventional latching devices, we modified the circuit parameters and layout design based on specifications of the new fabrication process. We have obtained operations for the 256-bit RAM with a bit yield of 100%, the lK-bit RAM with a bit yield of 99.8%, and the 4K-bit RAM with a bit yield of 96.7%. The number of defects in the 4K-bit RAM was estimated to be approximately 10. We confirmed that evaluations using the RAMs were effective at detecting defects due to the fabrication process.

Published in:

IEEE Transactions on Applied Superconductivity  (Volume:17 ,  Issue: 2 )