Download or read book Diamond Heteroepitaxy by Bias Enhanced Nucleation written by Vidhya Sagar Jayaseelan and published by . This book was released on 2008 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diamond has exceptional semiconducting and optical properties that can be used for a wide variety of new applications such as high temperature, high power devices, and optical windows. Exploitation of these properties of diamond needs the development of heteroepitaxial diamond growth process on traditional substrates such as Silicon and Silicon Carbide. Bias enhanced nucleation (BEN) followed by Plasma Enhanced Chemical vapor Deposition (PECVD) has been recognized as a promising route to achieve this goal. However, the BEN process for heteroepitaxy and its mechanism is not well understood. In this study, a system is designed and fabricated to enable the application of bias during diamond deposition in an ASTEX PECVD system, and heteroepitaxial diamond films are grown. The evolution of the oriented diamond film and its microstructure is studied by SEM, TEM, and XRD techniques revealing the formation of misoriented grains, extensive twinning and low angle grain boundaries. The effect of the BEN process conditions on the degree of orientation is investigated. It is observed that the orientation of the films improved at lower bias durations, methane flow rates and bias voltages. TEM images of the nucleation layer are analyzed, and the changes in the nucleation layer grain structure with process parameters are studied. Significant variation in the microstructure and grain size from an average of about 560 nm to about 10 nm is observed with change in process conditions. The BEN process is investigated and the nature of the deposit forming during this step is revealed using SEM, TEM and Raman spectroscopy to be predominantly a nanocrystalline diamond film along with rhombohedral and amorphous carbon. A simple model based on the formation of a nanocrystalline diamond particles during BEN, followed by their growth and coalescence under the plasma is proposed to describe the oriented film formation. The variations in microstructures and orientation are correlated with the process conditions under which they are formed.