Electrode coating for electron emission devices within cavities

A method for forming a field emission diode for an electrostatic discharge device, the method comprising:

• forming a first electrode, a sacrificial layer, and a second electrode, wherein the sacrificial layer separates the first and second electrode;
• forming a cavity between the first and second electrode by removing the sacrificial layer, wherein the cavity separates the first and second electrodes;
• and
• depositing an electron emission material on a surface of at least one of the first and second electrodes through at least one access hole after formation of the first and second electrodes, wherein the access hole is located remotely from a location of electron emission on the first or second electrodes;
• plugging the access hole after depositing the electron emission material and forming a vacuum or low gas pressure in the cavity, wherein the cavity is hermetically sealed.