Deposition of thick boron-doped homoepitaxial single crystal diamond by microwave plasma chemical vapor deposition

The deposition of high quality single crystal boron-doped diamond is studied. The experimental conditions for the synthesis of 1–2 mm thick boron-doped diamond are investigated using a high power density microwave plasma-assisted chemical vapor deposition reactor. The boron-doped diamond is deposited at a rate of 8–11.5 μm/h using 1 ppm diborane in the feed gas as the boron source, and the capability to overgrow defects is demonstrated. The experimental study also investigates the deposition of diamond with both 10 ppm diborane and 2.5–500 ppm of nitrogen added to the feedgas. Synthesized material properties are measured including the electrical conductivity using a four-point probe and the substitutional boron content using infrared absorption.