Field emission from heavily phosphorus-doped homoepitaxial diamond

Field emission characteristics of heavily phosphorus doped homoepitaxial diamond (111) after H-plasma treatment and wet chemical oxidization are discussed. Although H-terminated surface has a negative electron affinity (NEA), higher threshold voltage have to be applied compared to wet chemical oxidized surface with a positive electron affinity (PEA). From field emission results and surface characterizations, we conclude that a surface electric field is present which prevents electrons in the bulk of diamond to reach the vacuum level.