US 6,692,568 B2 · Method and apparatus for producing MIIIN columns and MIIIN materials grown thereon

Abstract

A method utilizes sputter transport techniques to produce arrays or layers of self-forming, self-oriented columnar structures characterized as discrete, single-crystal Group III nitride posts or columns on various substrates. The columnar structure is formed in a single growth step, and therefore does not require processing steps for depositing, patterning, and etching growth masks. A Group III metal source vapor is produced by sputtering a target, for combination with nitrogen supplied from a nitrogen-containing source gas. The III/V ratio is adjusted or controlled to create a Group III metal-rich environment within the reaction chamber conducive to preferential column growth. The reactant vapor species are deposited on the growth surface to produce single-crystal MIIIN columns thereon. The columns can be employed as a strain-relieving platform for the growth of continuous, low defect-density, bulk materials. Additionally, the growth conditions can be readjusted to effect columnar epitaxial overgrowth, wherein coalescence of the Group III nitride material occurs at the tops of the columns, thereby forming a substantially continuous layer upon which additional layers can be deposited. The intervening presence of the column structure mitigates thermal mismatch stress between substrates, films, or other layers above and below the columns. A high deposition rate sputter method utilizing a non-thermionic electron/plasma injector assembly is provided to carrying out one or more of the growth steps.

Claims93

Dependent claims

A method for producing single-crystal MIIIN columns comprising the steps of:

(a) providing a template material having an epitaxial-initiating growth surface;
(b) sputtering a Group III metal target in a reaction chamber to produce a Group III metal source vapor;
(c) introducing a nitrogen-containing gas into the reaction chamber;
(d) adjusting the III/V ratio of Group III metal source vapor to nitrogen to create a Group III metal-rich environment within the reaction chamber conducive to preferential column growth;
(e) combining the Group III metal source vapor with the nitrogen-containing gas to produce a reactant vapor species comprising Group III metal and nitrogen;
and
(f) depositing the reactant vapor species on the growth surface to produce single-crystal MIIIN columns thereon.

4 more elements

A method for producing a single-crystal MIIIN article comprising the steps of:

(a) providing a template material having an epitaxial-initiating growth surface;
(b) sputtering a Group III metal target in a plasma-enhanced reaction chamber to produce a Group III metal source vapor;
(c) introducing a nitrogen-containing gas into the reaction chamber;
(d) adjusting the III/V ratio of Group III metal source vapor to nitrogen-containing gas to create a Group III metal-rich environment within the reaction chamber conducive to preferential column growth;
(e) combining the Group III metal source vapor with the nitrogen-containing gas to produce a reactant vapor species comprising Group III metal and nitrogen;
(f) depositing the reactant vapor species on the growth surface to produce single-crystal MIIIN columns thereon;
and
(g) readjusting the III/V ratio to create an environment within the reaction chamber conducive to columnar epitaxial overgrowth;
(h) continuing to deposit the reactant species on the growing MIIIN columns, whereby uppermost regions of the MIIIN columns coalesce and grow to form a substantially continuous, single-crystal MIIIN layer;
and
(i) growing a bulk, single-crystal MIIIN article on the MIIIN layer.

8 more elements

Dependencies are inferred from the claim text.

Method and apparatus for producing MIIIN columns and MIIIN materials grown thereon

Life of this patent

Method and apparatus for producing MIIIN columns and MIIIN materials grown thereon

Life of this patent

Abstract

Claims93