Diamond single crystal substrate manufacturing method
A diamond single crystal substrate manufacturing method for growing by vapor-phase synthesis a single crystal from a diamond single crystal seed substrate, comprising etching away by reactive ion etching, prior to single crystal growth, at least 0.5 μm and less than 400 μm, in etching thickness off the surface of the seed substrate which has been mechanically polished, thereby removing from the surface of the seed substrate the work-affected layers caused by mechanical polishing; and growing then a single crystal thereon. The manufacturing method provides a diamond single crystal substrate having a high quality, large size, and no unintentional impurity inclusions, and suitable for use as semiconductor materials, electronic components, optical components or the like.
1. A diamond single crystal substrate manufacturing method by growing a single crystal from a diamond single crystal seed substrate by vapor-phase synthesis, said method comprising etching away by reactive ion etching, prior to single crystal growth, at least 0.5 μm and less than 400 μm, in etching thickness, off a main face and at least 50 nm, in etching thickness, off outer peripheral side faces of the seed substrate which has been mechanically polished, and growing then a single crystal thereon.
2. The method according to claim 1 , wherein an etching gas in said reactive ion etching is a mixture gas of oxygen and carbon fluoride.
3. The method according to claim 1 , wherein an etching pressure in said reactive ion etching is at least 1.33 Pa and no more than 13.3 Pa.
4. The method according to claim 1 , wherein the substrate temperature during etching in said reactive ion etching is 800K or less.