Mit Diamant beschichtetes AlN-Substrat und Verfahren zum Herstellen

A device, comprising:

• with
• a substrate made of aluminum nitride, wherein said substrate comprises an upper side and a lower side, wherein the lower side is (6) opposite the upper side;
• a diamond layer coated on the upper side of the substrate;
• a coated area coated on the lower side comprising a carbon-based coating containing at least 50% sp2 configured carbon;
• and
• a free area as part of the lower side, wherein the free area comprises a thinner carbon-based coating that is thinner than the carbon-based coating on the coated area of the lower side,
• wherein, irrespective of a thickness profile of the carbon-based coating in the coated area of the lower side, a thickness of the thinner carbon-based coating in the free area is less than in a part of the coated area that immediately surrounds or abuts the free area
• wherein the free area constitutes at most 10% of the lower side of the substrate