Computer-controlled ion beam deposition systems for high T c superconductor and other multi-component oxide thin films and layered structures

Abstract

A single beam, multiple target (SBMT) deposition system which features a rotating target holder with either elemental or simple compound targets has been developed for the production of layered thin film structures and multicomponent oxide, silicade or other compound thin films. We are employing the SBMT ion beam sputtering system for the deposition of high temperature superconducting, electro-optic and ferroelectric thin films and multilayered structures. The beam-target-substrate geometry and ion beam characteristics are designed to minimize scattering of the ion beam from the target (which results in resputtering of, and inert gas incorporation into the film) while maintaining high deposition rates. The amount of energy which is deposited into the film may be controlled by means of a secondary reactive or inert ion beam impacting on the growing film. This secondary beam may provide enough energy to promote activated processes, such as the in-situ formation of oriented crystal structures of high temperature superconducting materials. All parameters necessary to control the film properties are under computer control. A deposition cycle, defined as a number of sequential steps, may be easily modified or added to previously existing deposition cycles, thereby permitting the creation of complicated deposition procedures suitable for the production of films with highly reproducible properties for research purposes, and the in-situ fabrication of complex devices for technological applications. Examples are given of the capabilities of the technique as they apply to the production of high T c superconducting devices.