Abstract: A growth substrate adapted for making by epitaxy an array of InGaN based diodes, including mesas M(i), made of GaN based crystalline materials, each including N doped layers, with N?2, separated in pairs by an insulation intermediate layer made of a non-porous material, and each having a free upper face adapted for making a diode of the array by epitaxy; the mesas being configured according to at least three different categories including: a so-called M(N) mesas category where the N doped layers are porous; a so-called M(0) mesas category where none of the doped layers (13, 15) is porous; and a so-called M(n) mesas category where n doped layers are porous, with 1?n<N.