Manufacturing method of SiC composite substrate

A method for producing a SiC composite substrate comprising a monocrystalline SiC layer on a polycrystalline SiC substrate, the method comprising, in order, the steps of:

• providing a monocrystalline SiC layer on one side of a support substrate made of silicon so as to produce a monocrystalline SiC layer carrier;
• producing a SiC laminate comprising the monocrystalline SiC layer and a polycrystalline SiC substrate of thickness t stacked on the support substrate, by using a chemical vapor deposition process to deposit polycrystalline SiC on the monocrystalline SiC layer and then cooling, said deposition of the polycrystalline SiC comprising
• (i) heating the monocrystalline SiC layer carrier to below 1,414° C. and depositing thereon only part of the polycrystalline SiC substrate, which is a thickness t1 of at least 30 μm, and
• (ii) subsequently raising the temperature to 1,414° C. or above and additionally depositing polycrystalline SiC up to the thickness t, which is at least 100 μm and not more than 650 μm, while melting at least part of the support substrate;
• and
• physically and/or chemically removing the support substrate.