초록 ▼

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 t

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 .gtoreq.20 um.sup.2.

대표청구항 ▼

[ What is claimed is:] [1.] A process for making a substrate having a polycrystalline diamond layer and formed from a material selected from the group consisting of AlN and Si.sub.3 N.sub.4, with at least 75% of the interface between the substrate and the diamond layer being covered by diamond cryst

[ What is claimed is:] [1.] A process for making a substrate having a polycrystalline diamond layer and formed from a material selected from the group consisting of AlN and Si.sub.3 N.sub.4, with at least 75% of the interface between the substrate and the diamond layer being covered by diamond crystals, each diamond crystal having a contact area with the substrate of .gtoreq.20 .mu.m.sup.2, said process comprising the steps of chemically the substrate for 5 to 60 seconds by using a solution selected from the group consisting of potassium hydroxide and sodium hydroxide or by using a melt selected from the group consisting of KOH and NaOH having a concentration of 40 to 60%, said chemically etching process being carried out at an ambient temperature of 300 to 500.degree. C.; and depositing the diamond layer on the substrate from a gas phase.