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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. 

There is a growing need for digital and power electronics to deliver higher power for applications in batteries for electric vehicles, energy sources from wind and solar, data centers, and microwave devices. The higher power also generates more heat, which requires better thermal management. Diamond thin films and substrates are attractive for thermal management applications in power electronics because of their high thermal conductivity. However, deposition of diamond by microwave plasma enhanced chemical vapor deposition (MPECVD) requires high temperatures, which can degrade metallization used in power electronic devices. In this research, titanium (Ti)–aluminum (Al) thin films were deposited by DC magnetron sputtering on p-type Si (100) substrates using a physical mask for creating dot patterns for measuring the properties of the contact metallization. The influence of processing conditions and postdeposition annealing in argon (Ar) and hydrogen (H2) at 380 °C for 1 h on the properties of the contact metallization is studied by measuring the I-V characteristics and Hall effect. The results indicated a nonlinear response for the as-deposited films and linear ohmic contact resistance after postannealing treatments. In addition, the results on contact resistance, resistivity, carrier concentration, and Hall mobility of wafers extracted from Ti–Al metal contact to Si (100) are presented and discussed. 

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.