Diamond electrode and method of manufacturing the same

A method of manufacturing a diamond electrode, the method comprising:

• sanding a surface of a substrate by alumina sanding media of which a grain size is 100 μm to 150 μm, and imparting roughness to the surface of the substrate;
• forming a carbide layer on the surface of the substrate by introducing hydrogen and a carbon source gas into a vacuum chamber, wherein the forming of the carbide layer comprises forming a niobium carbide layer on a niobium substrate by introducing hydrogen and a carbon source gas in a mixing ratio of 100:1.5, the hydrogen and the carbon source gas being introduced at a time point at which a temperature of the surface of the substrate is increased to 600° C.˜700° C., wherein the forming of the carbide layer is performed for 10-30 minutes such that the niobium carbide layer is formed to have a thickness smaller than 1 μm;
• then
• at a time point at which the temperature of the surface of the substrate is increased to a first temperature in a range of 750° C.˜800° C., depositing a first boron-doped diamond layer directly on the carbide layer by hot-filament chemical vapor deposition (HFCVD) on the carbide layer by introducing methane (CH4), TMB (trimethylboron, 0.1% C3H9B), and hydrogen (H2) into the vacuum chamber in a first ratio of 0.5-2.5:3-5:100 (methane:TMB:hydrogen) for a first process time during which the temperature of the surface of the substrate is maintained as the first temperature;
• after the first process time, stopping the depositing of the first boron-doped diamond layer, wherein the first boron-doped diamond layer deposited during the first process time has a thickness of 1-2 μm;
• then
• depositing a second boron-doped diamond layer directly on the first boron-doped diamond layer by hot-filament chemical vapor deposition (HFCVD) by introducing methane (CH4), TMB (trimethylboron, 0.1% C3H9B), and hydrogen (H2) into the vacuum chamber in a same ratio as the first ratio for a second process time during which the temperature of the surface of the substrate is maintained same as the first temperature;
• after the second process time, stopping the depositing of the second boron-doped diamond layer, wherein the second boron-doped diamond layer deposited during the second process time has a thickness of 1-2 μm,
• wherein the first boron-doped diamond layer has a pinhole, and the second boron-doped diamond layer is deposited directly on the first boron-doped diamond layer to cover the pinhole,
• wherein the first boron-doped diamond layer has a first surface in contact with the carbide layer and a second surface opposite to the first surface, and the second boron-doped diamond layer covers and comes in direct contact with substantially the entire second surface of the first boron-doped diamond layer,
• wherein the first and second boron-doped diamond layers are deposited on the carbide layer, such that a thickness of a combination of the first boron-doped diamond layer and the second boron-doped diamond layer that covers the pinhole of the first boron-doped diamond layer is 3 to 5 μm.