Electron affinity and surface re-ordering of homoepitaxial diamond (100)

The change in electron affinity and the re-ordering of the diamond surface upon annealing of a homoepitaxially grown diamond (100) thin film were investigated by ultraviolet photoemission spectroscopy low energy electron diffraction (LEED), and Auger electron spectroscopy. When the sample was heated to ∼ 1250°C, the electron affinity of the sample changed from negative to positive and the LEED pattern changed from (2 × 1/1 × 2) to (1 × 1) When the sample was further annealed at ∼ 900°C, the electron affinity and the LEED pattern reverted to negative and (2 × 1/1 × 2) respectively. The sample was then heated to ∼ 1100°C, followed by annealed at ∼ 900°C again, and the same phenomenon was observed. These observations were considered to be associated with the disordering/re-ordering behavior of the diamond surface upon annealing.