Oxidization process of CVD diamond (1 0 0):H 2 × 1 surfaces

We have investigated atomic structures of B-doped microwave-plasma chemical vapor-deposited diamond (1 0 0) surfaces using an ultra-high-vacuum scanning tunneling microscope (STM). Most of STM images taken from the diamond surfaces at the very initial oxidization stage reflected the original surface atomic regularity of the diamond (1 0 0):H 2 × 1/1 × 2 structures while some of these images demonstrated a distinctive feature clearly differing from those of the original hydrogen-terminated surfaces. A further oxidization of the diamond surfaces resulted in the appearance of another specific feature in larger surface areas. Possible oxygen sites and oxidization process of hydrogen-terminated diamond (1 0 0) surfaces are discussed in relation to preferential oxidizations of CC dimer bonds, based upon our STM observations.