Dependence of RF power on the phase transformation for boron nitride films deposited on graphite at room temperature

• Published in: Journal of crystal growth 2009-07, Vol.311 (14), p.3716-3720
• Main Authors: Yang, Xuxin, Li, Hongdong, Li, Yingai, Lü, Xianyi, Gao, Shiyong, Zhu, Pinwen, Zhang, Qing, Zhang, Tiechen, Zou, Guangtian
• Format: Article
• Language: English
• Subjects: A1. Crystal structure; A3. Physical vapor deposition processes; B1. Nitrides; B2. Semiconducting III–V materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Materials science; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2009.04.041

Cubic boron nitride (cBN) thick films deposited on mainly c-axis-oriented graphite substrate at room temperature and zero bias by radio frequency (RF) magnetron sputtering were studied. In the growth process, RF power plays a key role in determining the content of cubic phase in films, while the conventional substrate heating and biasing have been neglected. With increase in RF power, the dominated content of films converts from explosion boron nitride (eBN) to cBN. The transformation mechanism has been discussed. The unique structural properties of the “soft” graphite are favorable to propose simple conditions for growing “hard” cBN films. Furthermore, the optical band gap of BN films having ∼90% cubic phase is of ∼5.8 eV obtained from ultraviolet–visible optical transmission measurement. The electron field emission examination shows that cBN film on graphite has a high emission current density of 2.8×10 −5 A/cm 2 at an applied field of ∼30 V/μm.