Adsorption, migration and growth behaviors of N and C on nitrogen-doped H-terminated diamond (100) surfaces: A theoretical and experimental study

Diamond has shown great potential in high-power electronics due to its exceptional physical and chemical properties, where nitrogen doping is critical in microwave plasma chemical vapor deposition (MPCVD) growth. To investigate the effects of nitrogen doping on the adsorption behavior of N and C atoms during diamond growth, this study systematically analyzes their adsorption energies, migration barriers, and structural variations on nitrogen-doped hydrogen-terminated diamond (100) surfaces using first-principles calculations. Complementary experiments are conducted to evaluate the influence of nitrogen doping levels on diamond growth rate, residual stress, and crystalline quality. The computational results reveal that surface nitrogen doping induces localized electronic rearrangement and spin polarization, which in turn significantly weakens the stability of surface C H bonds and enhances the adsorption activity of elements such as N and C. It also facilitates hydrogen desorption and generates new active sites on the growth surface. Moreover, nitrogen doping induces localized lattice compressive stress. Experimental results, including dynamic secondary ion mass spectrometry (D-SIMS) for quantifying nitrogen concentrations and Raman spectroscopy and X-ray rocking curve (XRC) measurements, confirm that increased nitrogen doping correlates with enhanced residual stress and reduced crystalline quality. Theoretical and experimental results show that nitrogen doping promotes the regeneration of active sites on the diamond surface, enhances surface reactivity, and induces local compressive stress. Surface nitrogen doping modulates local electronic structure and surface bonding characteristics through electron transfer, thereby effectively increasing adsorption strength and chemical reactivity. This work provides both an explanation and guidance for the controlled growth of nitrogen-doped diamond. • DFT reveals that nitrogen doping induces spin polarization and orbital hybridization, resulting in a 7.748 eV increase in the carbon adsorption energy at the S2 site. • DFT-NEB calculations reveal that nitrogen doping raises carbon migration barriers, enhancing carbon trapping and accelerating diamond growth. • DFT shows that nitrogen doping enhances carbon adsorption by electron transfer, weakens C H bonds, and lowers hydrogen abstraction energy by 4.29 eV. • DFT and experiments show that nitrogen doping elongates C N bonds and contracts atoms, increasing compressive stress with rising nitrogen content.