THE SYNTHESIS AND CHARACTERIZATION OF PHOSPHORUS-DOPED DIAMOND FILMS USING TRIMETHYL-PHOSPHITE AS A DOPING SOURCE

Producing impurity-doped diamond films is a critical task for modern e lectronic applications. In this study, the effects of phosphorus in th e gas phase on the morphological features of polycrystalline diamond f ilms were investigated. The diamond films were prepared on n-type Si(1 00) substrates by the microwave plasma chemical vapour deposition. A t rimethyl-phosphite vapour was introduced to the CH4-CO2 gas mixture as a dopant source. Surface morphology changed from well-defined facets to ball-like features by increasing the dopant concentration in the ga s phase. Phosphorus-doped diamond films of good quality and well defin ed facets could be obtained by reducing the carbon concentration of re actant gases. This reduction could be achieved by decreasing the CH4 f low rates during the deposition process. An increase in the the dopant source caused the growth rate to become lower, the nucleation density to reduce drastically, and the relative intensity of XRD characterist ic (110) peak to increase significantly.