Chemisorption of fluorine, hydrogen and hydrocarbon species on the diamond C(111) surface

AES, XPS, TDS and LEED have been used to study the interactions of F, H and CH x species with the diamond C(111)-(2 × 1) surface. It is found that a small quantity of chemisorbed H atoms can induce the (2 × 1) to (1 × 1) phase transformation and uphold the sp3 structure to nearly 1400K. In contrast, F atoms and CH x species are unable to do so. The distinct bonding characteristics of these adsorbates manifest clearly the diverse effects on the surface electronic and geometrical structures. It is further shown that H can react with and replace the preadsorbed CH x , while subsequent exposure to CH x can do the same to the preadsorbed H atoms. The results are relevant to a better understanding of the basic mechanisms involved in the diamond CVD process.