Enhancing the Quality of Diamond Film Growth Through the Synergistic Addition of Nitrogen and Carbon Dioxide

This study investigates the synergistic effects of co-doping with ultralow-concentration nitrogen and trace carbon dioxide on the growth of polycrystalline diamond films via microwave plasma chemical vapor deposition (MPCVD). The films were characterized using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and photoluminescence spectroscopy. Results indicate that trace nitrogen effectively promotes oriented growth and enhances the deposition rate, whereas excessive nitrogen leads to the formation of defects such as pores and microcracks. The introduction of CO2 suppresses the formation of nitrogen-vacancy-related defects through a selective etching mechanism. Under co-doping conditions, diamond films with high growth rates, strong texture, and superior thermal conductivity (up to 1863.94 W·m−1·K−1) were successfully synthesized, demonstrating significant potential for thermal management applications in high-power integrated circuits.