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Diamond is a wide bandgap semiconductor possessing unique properties for applications in quantum systems and ultra-wide bandgap electronics, which require a fundamental understanding of processing of high-quality diamond crystals and textured films by microwave plasma-enhanced chemical vapor deposition (MPECVD). The approach of bias-enhanced nucleation (BEN) followed by growth is studied for the processing of oriented diamond film with azimuthal texture. The magnitude of the applied electric field is shown to play an important role in the processing of the highly azimuthally textured diamond film on Si (100) substrate. The X-ray diffraction pole figure, scanning electron microscopy, and Raman spectroscopy results show that an optimum applied electric field during BEN and microwave plasma conditions leads to the formation of diamond film with azimuthal texture upon growth by MPECVD. These results are promising for fabricating diamond films of optimum characteristics containing nitrogen-vacancy (NV) defect centers for application in quantum devices. 

Nucleation is important in processing of good quality diamond crystals and textured thin films by microwave plasma enhanced chemical vapor deposition (MPECVD) for applications in quantum devices and systems. Bias-enhanced nucleation (BEN) is one approach for diamond nucleation in situ during MPECVD. However, the mechanism of diamond nucleation by BEN is not well understood. This paper describes results on the nucleation of diamond within a carbon film upon application of electric field during the BEN-facilitated MPECVD process. The nature of the diamond film and nuclei formed is characterized by SEM (scanning electron microscopy), Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). The HRTEM images and associated diffraction patterns of the nucleation layer show that the diamond nuclei are formed within the carbon film close to the Si (100) substrate surface under the influence of microwaves and electric fields that lead to formation of the textured diamond film and crystal upon further growth. These results are expected to develop diamond films of optimum quality containing a nitrogen-vacancy center for application in quantum systems.