Method for producing a crystalline layer in a III-N compound by van der Waals epitaxy from graphene
The invention relates to a method for manufacturing a layer of interest (3) in a III-N crystalline compound by epitaxy from a layer of graphene (2), characterized in that it comprises, prior to a phase of nucleation of the layer of interest (3), a step of thermal treatment of the layer of graphene (2) in which it is subjected to a first temperature (T tt ) no lower than 1050° C. and to a stream of ammonia.
1. A process for fabricating a layer of interest of a crystalline III-N compound by epitaxy from a graphene layer, the process comprising:
obtaining a graphene layer on a support layer;
prior to a nucleation phase of the layer of interest:
subjecting the supported graphene layer to an ammonia pressure of 600 to 800 mbar at a first temperature (Ttt) of 1050° C. or more;
performing the epitaxy nucleation phase of the III-N compound on the ammonia treated supported graphene at a temperature (T2) below 1050° C.; and
performing an epitaxy growth phase of the III-N compound on the ammonia treated supported graphene to obtain the crystalline III-N compound on the supported graphene layer.
2. The process of claim 1 , wherein a temperature of the epitaxy growth phase is a third temperature (Tc) higher than the second temperature (T2) and lower than 1050° C.
3. The process of claim 2 , wherein ammonia is a precursor of the nitrogen of the III-N compound during the nucleation and growth phases of the III-N compound of the layer of interest.
4. The process of claim 1 , wherein the support layer comprises hexagonal silicon carbide (SiC).
5. The process of claim 1 , wherein the graphene layer consists of one to at most five graphene sheets.
6. The process of claim 1 , wherein the III-N compound is selected from the group consisting of GaN, AlGaN, InGaN, and AlInGaN.
7. The process of claim 1 , wherein the crystalline III-N compound is deposited epitaxially by metal-organic chemical vapor deposition.
8. The process of claim 1 , wherein the III-N compound is In x1 Ga 1-x1 N with an atomic proportion of indium x1 of 5% or more.
9. A process for fabricating an optoelectronic device, comprising fabricating a layer of interest by performing the process of claim 1 , and then fabricating from the layer of interest N and P doped layers between which an active zone is located, the active zone comprising at least one quantum well made from the III-N compound.
10. The process of claim 9 , wherein the III-N compound of the layer of interest is InGaN with an atomic proportion of indium of 5% or more, and the active zone is made from InGaN with an atomic proportion of indium of 15% or more.