US 4,923,585 AGranted

Sputter deposition for multi-component thin films

AssigneeArch Development Corporation

InventorsAlan R. Krauss, Orlando Auciello

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Abstract

Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams.

Claims20

Dependent claims

Apparatus for the deposition of a thin film on a substrate by sequential beam-induced desorption from multiple targets, on a substrate wherein atoms of each of said targets are deposited in a layer having a predetermined thickness in a cyclic manner until a desired thickness of said film is deposited, said apparatus comprising:

beam generating means for providing a single, fixed energetic beam;
a plurality of targets each comprised of a selected composition;
displacement means coupled to said beam generating means or to each of said targets for sequentially aligning said beam with each of said targets, whereupon atoms of a target which is aligned with said beam are desorbed from said target and are deposited on the substrate;
detection means responsive to the atoms deposited on the substrate for comparing the thickness of a layer of the thus deposited atoms with said predetermined thickness;
control means coupled to said detection means and to said displacement means for removing said one of said targets from alignment with said beam and for aligning another one of said targets with said beam when the thickness of the layer of the thus deposited atoms equals said predetermined thickness for permitting atoms of said another one of said targets to be deposited on the substrate;
and
support means for supporting said substrate and said detection means in a spaced manner such that said beam is directed intermediate said substrate and said detection means and is incident generally normal upon the targets such that the atoms of a target aligned with said beam are desorbed from the target and directed back toward said support means and onto said substrate and said detection means, and wherein said substrate and said detection means are disposed symmetrically on opposed sides of said beam.

4 more elements

Dependencies are inferred from the claim text.