Atomic Layer Deposition Josephson Junctions for Cryogenic Circuit Applications

Jhabvala, Christine A ; Nagler, Peter C ; Nagler, Peter C

关键词: DEPOSITION;    JOSEPHSON JUNCTIONS;    CRYOGENICS;    INSULATION;    ATOMIC PHYSICS;   

RP-ID  :  GSFC-E-DAA-TN70971

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Superconducting-insulating-superconducting (SIS) trilayers have been produced for Josephson Junction fabrication by thermal atomic layer deposition (ALD) processes. The trilayers are composed of alternating layers of Ti0.4N0.6/Al2O3/ Ti0.4N0.6, deposited at 450°C, in a thermal ALD reactor on Al2O3-coated silicon. The conformal nature of the ALD process provides excellent step coverage of superconducting and insulating films. The film thickness of a single ALD cycle being one mono-layer, allows us to precisely control the tunnel-barrier insulator thickness by counting the number of ALD cycles during the insulator deposition step. Tunnel-junctions with critical current 500 A/cm2 are reported. Fabrication of Josephson Junctions and progress toward development of a single-element ALD Superconducting Quantum Interference Device (SQUID) will be discussed