Combinatorial synthesis of material chips

Abstract

Systems and methods for providing in situ, controllably variable concentrations of one, two or more chemical components on a substrate to produce an integrated materials chip. The component concentrations can vary linearly, quadratically or according to any other reasonable power law with one or two location coordinates. In one embodiment, a source and a mask with fixed or varying aperture widths and fixed or varying aperture spacings are used to produce the desired concentration envelope. In another embodiment, a mask with one or more movable apertures or openings provides a chemical component flux that varies with location on the substrate, in one or two dimensions. In another embodiment, flow of the chemical components through nuzzle slits provides the desired concentrations. An ion beam source, a sputtering source, a laser ablation source, a molecular beam source, a chemical vapor deposition source and / or an evaporative source can provide the chemical component(s) to be deposited on the substrate. Carbides, nitrides, oxides, halides and other elements and compounds can be added to and reacted with the deposits on the substrate.

Description

FIELD OF THE INVENTION [0001] This invention relates to methods and systems for deposition of chemicals in controllably variable amounts on a substrate. BACKGROUND OF THE INVENTION [0002] In the past decade, several workers have applied a combinatorial synthesis approach to development of new materials, or to construction of known materials in new ways. Material chip samples, with varying chemical compositions involving two or three components and with discrete or continuous composition change, can, in principle, be synthesized, using multilayers and masks. However, a true multi-composition compound probably cannot be formed unless each multilayer is formed and uniformly diffused at relatively low temperatures. This appears to require an in situ approach, which is not well understood and is not developed in the background art. [0003] What is needed is an in situ approach and / or a multilayer approach for formation of chemical compounds having two, three or more components and having ...

AI Technical Summary

Benefits of technology

[0004] These needs are met by the invention, which provides several systems and associated methods for controllably variable in situ or multilayer deposition of two or more chemical components on a substrate. In one embodiment, an ultra-high vacuum (UHV) ion beam sputtering system or evaporation system includes a multi-target carousel, a precision mask that is movable in one or two coordinate directions, x and y, and a stepper motor to move the mask by controllable amounts in the x- and / or y-directions in a timed sequence. Pure metal sputtering or evaporation targets are used to deposit precursors in selected layers. Use of a UHV environment ensures that the precursor layers are not oxidized during or after deposition. A heating element, built into or associated with a sample holder, provides thermally-driven precursor diffusion after the deposition, without exposing the sample to air during sample transfer. Ion beam sputtering has several advantages: target exchange is relatively simple; most metal targets are available; and precursor interdiffusion occurs at much lower temperatures and over shorter time intervals than are required for distribution of metal-inorganic compounds. As a further benefit, where a second ion gun is added to the assembly, oxides, nitrides, carbides, halogens and similar substances can be formed in situ from the metal precursor films.

[0005] A second embodiment involves a chemical vapor deposition (CVD) approach and provides large area uniformity for the deposition, the possibility of co-deposition of multi-component thin films with individually controllable growth rates, and control of growth of the profile.

Problems solved by technology

However, a true multi-composition compound probably cannot be formed unless each multilayer is formed and uniformly diffused at relatively low temperatures.

This appears to require an in situ approach, which is not well understood and is not developed in the background art.

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