Superconducting integrated circuit with NbN SNS Josephson junction and manufacturing method thereof

Abstract

The invention provides a superconducting integrated circuit with a NbN SNS Josephson junction and a manufacturing method thereof.The superconducting integrated circuit comprises a substrate, a functional layer, a first isolation layer, a first wiring part, a second wiring part, a second isolation layer, a first grounding layer and a second grounding layer, the functional layer is located on the upper surface of the substrate and comprises a bottom electrode, a junction barrier layer and a top electrode, and the junction barrier layer is located on the upper surface of the substrate and comprises a first electrode and a second electrode; the first isolation layer covers the upper surface of the substrate and the exposed surface of the functional layer and is provided with a first contact hole and a second contact hole, and the first wiring part and the second wiring part fill the first contact hole and the second contact hole respectively. The second isolation layer covers the upper surface of the first isolation layer and the exposed surfaces of the first wiring part and the second wiring part and is provided with a first through hole and a second through hole. The first grounding layer and the second grounding layer respectively fill the first through hole and the second through hole. According to the Josephson junction unit, the thicker metal nitride is used as the junction barrier layer, so that the critical current density of the Josephson junction unit is improved, and the highest working frequency of the circuit is improved.

Description

technical field [0001] The invention belongs to the field of superconducting electronics, and relates to a superconducting integrated circuit with NbN SNS Josephson junction and a manufacturing method thereof. Background technique [0002] The superconducting single flux quantum (SFQ) circuit uses the presence or absence of a single flux quantum in a Josephson junction to represent logic information, which has the advantages of high speed and low power consumption. A superconducting digital integrated circuit is a multilayer structure with a Josephson junction as the core unit, and its circuit frequency is highly dependent on factors such as the critical current density, characteristic voltage, and hysteresis of the IV curve of the Josephson junction. [0003] At present, superconducting integrated circuits often use Nb / Al-AlOx / Nb Josephson junctions with extremely high critical current density and no shunt intrinsic damping. The operating frequency is 770GHz. This kind of...

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Problems solved by technology

[0005] In view of the above-mentioned shortcoming of prior art, the object of the present invention is to provide a kind of superconducting integrated circuit with NbN SNS Josephson junction and manufacturing method thereof, for solving the lower working temperature of SFQ circuit in the prior art and raising Difficult Problems of Critical Current Density and Maximum Operating Frequency of Josephson Junction Unit in SFQ Circuit

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