Abstract
A novel type of flat electron emission diode with a high emission efficiency has been fabricated using single crystalline diamond thin films homoepitaxially grown on thick high-pressure-synthesized diamond. For the formation of the buried electrode, 180-keV N+ ions were implanted into the homoepitaxial layer grown by microwave plasma chemical-vapor-deposition (CVD) method to a dose 1×1016 ions/cm2 at room temperature. Since this process created a significant damage in the specimen surface layer working as the electron emission surface, a high quality diamond layer was subsequently overgrown to recover the damaged surface. Applying voltages of sub-kV between the hydrogenated surface and the buried electrode results in an efficient electron emission (>10%).