Method of depositing a polycrystalline diamond layer on a nitride substrate

摘要

A method of depositing a polycrystalline diamond layer on a nitride substrate is disclosed, which comprises chemically-etching the nitride substrate with a KOH or NaOH solution or melt and depositing the polycrystalline diamond layer on the nitride substrate from a vapor phase, wherein the etching temperature, time and concentration of the etchant are controlled so that at least 75% of the interface between the substrate and the diamond layer is covered by diamond crystals, each diamond crystal having a contact area with the substrate of >/=20 um2.