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 <111> 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 <111> 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.