High throughput continuous pulsed laser deposition process and apparatus

Abstract

The present invention relates to an apparatus and method for forming a high-temperature superconducting film on a long tape substrate at speeds suitable for large-scale production. The method includes a spooling system for use in a high-throughput, continuous pulsed laser deposition (PLD) process in which a superconducting layer, such as yttrium-barium-copper-oxide (YBCO), is deposited atop a buffered metal substrate tape that is translated through one or more deposition chambers via the action of a reel-to-reel spooling system and a conductive-radiant multi-zone substrate heater. It also optionally includes a multi-target manipulator apparatus and multiple laser beams in which multiple targets are impinged upon simultaneously.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus and method for forming a high-temperature superconducting film on a long tape substrate at speeds suitable for large-scale production, includes a spooling system for use in a high-throughput, continuous pulsed laser deposition (PLD) process. BACKGROUND OF THE INVENTION [0002] In the past three decades, electricity has risen from 25% to 40% of end-use energy consumption in the United States. With this rising demand for power comes an increasingly critical requirement for highly reliable, high quality power. As power demands continue to grow, older urban electric power systems in particular are being pushed to the limit of performance, requiring new solutions. [0003] Wire forms the basic building block of the world's electric power system, including transformers, transmission and distribution systems, and motors. The discovery of revolutionary high-temperature superconductor (HTS) compounds in 1986 led to the ...

AI Technical Summary

Benefits of technology

[0044] In operation, the multi-target manipulator apparatus, having multiple target holders upon which are placed multiple targets, respectively, allows multiple laser beams to impinge simultaneously upon the targets. As a result, multiple plumes of ablated material, to which a substrate is exposed for a prede...

Problems solved by technology

As power demands continue to grow, older urban electric power systems in particular are being pushed to the limit of performance, requiring new solutions.

However, to date only short lengths of coated conductor wire samples have been fabricated at high performance levels with any of the conventional fabrication processes.

However, to date only short lengths of coated conductor wire samples have been fabricated at high performance levels using prior art vapor deposition processes and equipment.

While this represents a step toward the large-scale production of HTS coated tape, it is limited in its scalability.

To achieve significantly longer lengths of HTS coated tape the cylindrical substrate holder must increase in size accordingly, making it impractical to be housed within the main vapor deposition chamber.

Thus, a drawback of the vapor deposition process described in Youm is that the system is not easily scalable to produce long lengths (e.g, several kilometers) of HTS coated tape and is therefore not suited for the large-scale production of HTS coated wire.

A first challenge to the continuous deposition of HTS tapes utilizing a reel-to-reel tape transport system that is not overcome by Youm is the maintenance optimum tape tension throughout the extended deposition runs necessary to high-throughput systems.

This results in a variation in the target-to-substrate distance and a compromise of the thin film uniformity.

A second technical challenge to the continuous deposition of HTS tapes utilizing a reel-to-reel tape transport system that is not overcome by Youm is the maintenance of the tape at the optimal speed throughout extended deposition runs.

Lateral, as well as longitudinal, movement of the tape results in an inconsistent and non-uniform deposition resulting in variations in film thickness.

The importance of film uniformity cannot be an overemphasized: if there is an insufficient superconducting quality at a single point over the entire length of a few hundred meters of tape, the current carrying capacity of the entire length of tape is compromised.

Further, any elements that serve to position the tape must do so in such a way as to not induce stress or strain in the tape, which may damage the delicate thin films

Another technical challenge not overcome by Youm is how to wind ...

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