Effect of non-diamond carbon content on the spatial distributions of emission sites of the diamond films

• Published in: Diamond and related materials Vol. 9; no. 8; pp. 1506 - 1511
• Main Authors: Shim, Jae Yeob, Chi, Eung Joon, Baik, Hong Koo, Song, Kie Moon
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2000; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Diamond films; Electron and ion emission by liquids and solids; impact phenomena; Emission sites; Exact sciences and technology; Field emission; Field emission, ionization, evaporation, and desorption; Non-diamond carbon; Physics; Emission sites; Field emission; Non-diamond carbon; Diamond films; Raman spectra; Spatial distribution; Diamonds; SEM; Experimental study; IV characteristic
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/S0925-9635(00)00277-6

The influence of non-diamond carbon in diamond films on the spatial distributions of emission sites was investigated, and consequently the field emission mechanism was discussed. It was confirmed that when increasing the positive substrate bias or the CH 4/H 2 concentration ratio, the non-diamond carbon content in the resulting films was markedly increased and the surface morphologies of the films lost their unique facet shape. An increase of non-diamond carbon content improved significantly the field emission properties and caused a dramatic increase of emission sites. It was observed from the images of the films containing a small amount of non-diamond carbon that electron emission occurs predominantly at the sample edges and the reason for this phenomenon could be attributed to the surface electron emission. With increasing non-diamond carbon, the emission occurs at the center as well as at the edge of the sample. From this observation, it is proposed that the emission from central region was caused by a preferential transport through the conducting pathways such as grain boundaries.