A silicon-based niobium nitride thin film superconducting material and its manufacturing method

Abstract

The invention discloses a silicon substrate niobium nitride film superconducting material. The silicon substrate niobium nitride film superconducting material comprises a Si substrate, a TiN transitional layer and an NbN layer. An NbN film is directly arranged on the Si substrate in a growth mode to cause a big lattice mismatch degree so that a non-superconducting interface distortion layer with a certain thickness can exist in the NbN film, and superconducting performance of the NbN film is severely reduced. The TiN transitional layer and the NbN layer are of a face-centred cubic structure, the lattice mismatch degree is small, the TiN transitional layer is used for greatly reducing the interface distortion layer thickness of the NbN film, NbN crystallinity is simultaneously improved, and superconducting performance is improved accordingly. The NbTiN is high-Tc superconducting materials, and even if two elements including Ti and N in the TiN enter the NbN film, the Ti and the N are not reduced, and the superconducting performance of the Ti and the N is improved. The invention further provides a manufacturing method of the silicon substrate niobium nitride film superconducting material.

Description

technical field [0001] The invention relates to the field of superconducting material production, in particular to a silicon-based niobium nitride thin film superconducting material and a production method thereof. Background technique [0002] NbN (niobium nitride) thin film is the core material of various superconducting devices, such as superconducting tunnel junction (Superconducting tunnel junction), hot electron bolometer (HEB, Hot Electron Bolometer), superconducting single photon detection device (SSPD, SuperconductingSinglePhotonDetector), etc. . Usually, NbN thin films are prepared on MgO single crystal substrates by vacuum magnetron sputtering technology. The main consideration is that the lattice mismatch between NbN and MgO is small (~4%), and the grown NbN thin films have good superconducting properties. . However, the price of MgO single crystal substrate is high, the micro-nano processing technology of subsequent devices is immature, and the loss of devices...

AI Technical Summary

Problems solved by technology

However, these materials have two major disadvantages: one is that the crystal structure and lattice mismatch are still relatively large; the other is that the constituent elements of these materials will reduce the superconducting properties of NbN films if they diffuse into the NbN film

Therefore, there is still a gap between the existing Si-based NbN ultra-thin films and the superconducting properties of MgO-based NbN ultra-thin films. Exploring better transition layer materials to prepare Si-based NbN films can improve their superconducting properties. The material design and application range of superconducting thin films are very meaningful

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