Process for selective masking of III-N layers and for the preparation of free-standing III-N layers or of devices, and products obtained thereby

A process for the growth of an at least partially masked III-N layer by means of epitaxy, wherein III denotes at least one element of group III of the Periodic Table of Elements, selected from Al, Ga and In, the process comprising:

• providing a III-N layer having a surface, which comprises more than one facet;
• carrying out epitaxial growth under growth conditions;
• whereby a growth of at least one further III-N layer selectively on a first type or a first group of facet(s) and a deposition of mask material selectively on a second type or a second group of facet(s) proceed simultaneously.

A process for growth of an at least partially masked III-N layer by means of epitaxy in an epitaxy reactor, wherein III denotes at least one element of group III of the Periodic Table of Elements, selected from Al, Ga and In, the process comprising:

• performing epitaxial growth for the III-N layer, during at least a part of the growth process, under growth conditions where growth rates of lateral growth and vertical growth respectively are different;
• and
• supplying, during a period of respectively different lateral and vertical growth rates, at least one source for a mask material into the epitaxy reactor.