Lumilog

Other

Saint-gobain Cristaux Et Detecteurs

Saint-gobain Cristaux & Détecteurs

Pierre Gibart

Bernard Beaumont

Jean-Pierre Faurie

Eric Frayssinet

Gilles Nataf

Michel Vaille

Bernard Guillaume

Soufien Haffouz

Jean-Claude Guillaume

Therese Gibart, Legal Representative

High quality free standing GaN is obtained using a new modification of the Epitaxial Lateral Overgrowth technology in which 3D islands or features are created only by tuning the growth parameters. Smoothing these islands (2D growth) is achieved thereafter by setting growth conditions producing enhanced lateral growth. The repetition of 3D-2D growth results in multiple bending of the threading dislocations thus producing thick layers or free standing GaN with threading dislocation density below 10cm.

Process for growth of low dislocation density GaN

A method of manufacturing a low defect density GaN material comprising at least two steps of growing epitaxial layers of GaN with differences in growing conditions, (a.) a first step of growing an epitaxial layer GaN on an epitaxially competent layer under first growing conditions selected to induce island features formation, followed by (b.) a second step of growing an epitaxial layer of GaN under second growing conditions selected to enhance lateral growth until coalescence.

Process for producing an epitaxial layer of galium nitride

A method of manufacturing a low defect density GaN material comprising at least two step of growing epitaxial layers of GaN with differences in growing conditions, (a.) a first step of growing an epitaxial layer GaN on an epitaxially compentent layer under first growing conditions selected to induce island features formation, followed by (b.) a second step of growing an epitaxial layer of GaN under second growing conditions selected to enhance lateral growth until coalescence.

Process for producing an epitalixal layer of galium nitride

The invention concerns a method for preparing gallium nitride films by vapour-phase epitaxy with low defect densities. The invention concerns a method for producing a gallium nitride (GaN) film from a substrate by vapour-phase epitaxy deposition of gallium nitride. The invention is characterized in that the gallium nitride deposition comprises at least one step of vapour-phase epitaxial lateral overgrowth, in that at least one of said epitaxial lateral overgrowth steps is preceded by etching openings either in a dielectric mask previously deposited, or directly into the substrate, and in that it consists in introducing a dissymmetry in the environment of dislocations during one of the epitaxial lateral overgrowth steps so as to produce a maximum number of curves in the dislocations, the curved dislocations not emerging at the surface of the resulting gallium nitride layer. The invention also concerns the optoelectronic and electronic components produced from said gallium nitride films.

Method for producing by vapour-phase epitaxy a gallium nitride film with low defect density

Gallium nitride substrates are grown by epitaxial lateral overgrowth using multiple steps. On a masked substrate having openings areas, selective growth produces first triangular stripes in which most of the threading dislocations are bent at 90&#xb0;. In a second step, growth conditions are changed to increase the lateral growth rate and produce a flat (0001) surface. At this stage the density of dislocations on the surface is &#x3c;5&#xd7;107 cm 2. Dislocations are primarily located at the coalescence region between two laterally grown facets pinching off together. To further decrease the dislocation density a second masking step is achieved, with the openings exactly located above the first ones. Threading dislocations (TDs) of the coalescence region do not propagate in the top layer. Therefore the density of dislocations is lowered below &#x3c;1&#xd7;107 cm lover the entire surface.

Manufacturing gallium nitride substrates by lateral overgrowth through masks and devices fabricated thereof

The present invention relates to a process for producing an epitaxial layer of gallium nitride (GaN) as well as to the epitaxial layers of gallium nitride (GaN) which can be obtained by said process. Such a process makes it possible to obtain gallium nitride layers of excellent quality by (i) forming on a surface of a substrate, a film of a silicon nitride of between 5 to 20 monolayers, functioning as a micro-mask, (ii) depositing a continuous gallium nitride layer on the silicon nitride film at a temperature ranging from 400 to 600&#xb0; C., (iii) after depositing the gallium nitride layer, annealing the gallium nitride layer at a temperature ranging from 950 to 1120&#xb0; C. and (iv) performing an epitaxial regrowth with gallium nitride at the end of a spontaneous in situ formation of islands of gallium nitride.

Process for producing an epitaxial layer of gallium nitride

A process for producing an epitaxial layer of gallium nitride (GaN). A film of a dielectric whose thickness is about one monolayer is formed on a surface of a substrate. A continuous gallium nitride layer is then deposited on the dielectric film at a temperature sufficiently low to suppress island formation of the gallium nitride. The deposited gallium nitride layer is annealed at a temperature sufficiently high to promote island formation of the gallium nitride. An epitaxial regrowth with gallium nitride at the end of a spontaneous in situ formation of islands of gallium nitride then takes place. This method makes it possible to avoid having to use ex situ etching of masks by photolitographiy or chemical ethching techniques.

The invention concerns a method for producing a gallium nitride (GaN) epitaxial layer characterised in that it consists in depositing on a substrate a dielectric layer acting as a mask and depositing on the masked gallium nitride, by epitaxial deposit, so as to induce the deposit of gallium nitride patterns and the anisotropic lateral growth of said patterns, the lateral growth being pursued until the different patterns coalesce. The deposit of the gallium nitride patterns can be carried out ex-situ by dielectric etching or in-situ by treating the substrate for coating it with a dielectric film whereof the thickness is of the order of one angstrom. The invention also concerns the gallium nitride layers obtained by said method.

Growing community of inventors

Charcarncuf Grasse, France

Pierre Gibart