A process for obtaining a nitride (N) layer preferably obtained from at least one of gallium (Ga), indium (In) and aluminium (Al), characterised in that the process comprises the following steps: - providing a stack comprising a substrate and at least the following layers which are successively disposed from the substrate : ▪ a first layer, called flow layer , made of a material having a glass transition temperature, the flow layer having a glass transition temperature T glass transition ▪ a second layer, crystalline, called crystalline layer , which is different from the flow layer , - forming pads (1000a-1000e) by etching at least the crystalline layer and at least one portion of the flow layer so that: o each pad (1000a-1000e) includes at least: ▪ one first segment, called flow segment , formed by at least one portion of the flow layer , ▪ one second segment, crystalline, called crystalline segment , formed by the crystalline layer and surmounting the flow segment , o each pad (1000a-1000e) has a section whose maximum dimension is comprised between 10 and 500 nm (10 -9 metres), - epitaxially growing a crystallite (510a-510e) on at least some of said pads (1000a-1000e) and continuing the epitaxial growth of the crystallites (510a-510e) at least until coalescence of the crystallites (510a-510e) carried by two adjacent pads (1000a-1000e), so as to form said nitride layer , the epitaxial growth being performed at a temperature T epitaxy such that: T epitaxy ≥ k 1 . T glass transition , with k 1 ≥ 0.8 . - providing a stack comprising a substrate and at least the following layers which are successively disposed from the substrate : ▪ a first layer, called flow layer , made of a material having a glass transition temperature, the flow layer having a glass transition temperature T glass transition ▪ a second layer, crystalline, called crystalline layer , which is different from the flow layer , ▪ a first layer, called flow layer , made of a material having a glass transition temperature, the flow layer having a glass transition temperature T glass transition ▪ a second layer, crystalline, called crystalline layer , which is different from the flow layer , - forming pads (1000a-1000e) by etching at least the crystalline layer and at least one portion of the flow layer so that: o each pad (1000a-1000e) includes at least: ▪ one first segment, called flow segment , formed by at least one portion of the flow layer , ▪ one second segment, crystalline, called crystalline segment , formed by the crystalline layer and surmounting the flow segment , o each pad (1000a-1000e) has a section whose maximum dimension is comprised between 10 and 500 nm (10 -9 metres), o each pad (1000a-1000e) includes at least: ▪ one first segment, called flow segment , formed by at least one portion of the flow layer , ▪ one second segment, crystalline, called crystalline segment , formed by the crystalline layer and surmounting the flow segment , ▪ one first segment, called flow segment , formed by at least one portion of the flow layer , ▪ one second segment, crystalline, called crystalline segment , formed by the crystalline layer and surmounting the flow segment , o each pad (1000a-1000e) has a section whose maximum dimension is comprised between 10 and 500 nm (10 -9 metres), - epitaxially growing a crystallite (510a-510e) on at least some of said pads (1000a-1000e) and continuing the epitaxial growth of the crystallites (510a-510e) at least until coalescence of the crystallites (510a-510e) carried by two adjacent pads (1000a-1000e), so as to form said nitride layer , the epitaxial growth being performed at a temperature T epitaxy such that: T epitaxy ≥ k 1 . T glass transition , with k 1 ≥ 0.8 . <EOS>