ELSEVIER Thin Solid Films 280 (1996) 117-123 thin,.° Graphite formation on Ni film by chemical vapor deposition Masako Yudasaka a, Rie Kikuchi a, Takeo Matsui a, Yoshimasa Ohki a, Mark Baxendale a, Susumu Yoshimura a, Etsuro Ota b a Yoshimura m-Electron Materials Project, ERATO, JRDC, c/o Matsushita Research Institute Tokyo, inc., 3-10-1 Higashi-mita, Taraa-ku, Kawasaki 214, Japan b Department of Chemistry, Faculty of Engineering, Gunma University, Kiryu, Gunma 376, Japan Received 12 July 1995; accepted 30 October 1995 Abstract Thin film formation of graphite by chemical vapor deposition using 2-methyl-1,2'-naphthyl ketone as a starting material was carried out on Ni film substrates. On Ni films directly deposited on quartz glass, the graphite films were obtained when the Ni film thickness was above 1 000/~ and above 5 000/~ at 700 °C and 1 000 °C, respectively. Depositions on thinner Ni film substrates comprise amorphous carbon (a- C) or graphite tubes which was owing to the thermal coagulation of the Ni film into droplets. On the other hand, graphite film was obtained on the Ni film with thickness 10 A,when a-C was inserted between the Ni film and the quartz glass. The coagulation of the Ni film is considered to be avoided by inserting a-C layer. Keywords: Graphite; Nickel; Chemical vapor deposition 1. Introduction Substrate material dependence of the structure of carbo- naceous material deposited by the chemical vapor deposition (CVD) method has been studied within the authors' group. A Ni plate is found to be one of the best substrates for the low-temperature deposition of graphite [ 1-3]. The role of Ni in the CVD process is becoming apparent; dehydrogena- tion of certain organic material is found to be enhanced between 600 °C and 700 °C, the t~mperature range that cor- responds to graphite thin film formation by CVD [ 3 ]. On the other hand, graphite films can be formed from many organic materials by CVD on Ni above 800 °C. This agrees with the observation that Ni deposited on amorphous carbon (a-C) heat-treated above 800 °C enables recrystallization of carbon as graphite from the solid solution [ 3]. However, the Ni plate used as the substrate hinders eval- uation of the electrical and magnetic properties of the graphite thin film because its thickness of several hundreds ~m is several orders of magnitudes larger than that of the obtained graphite film. Usually the thickness of graphite thin film is less than several thousands angstroms. To avoid this problem, Ni thin films are used as the substrates rather than a Ni plate. This study reveals the structures of the graphite film formed by CVD o~ t,t',eNi films. 0040-6090/96/$15.00 © 1996 Elsevier Science S.A. All rights reserved SSD10040-6090 (95) 08224-7 2. Experimental The equipment for the vacuum CVD used in this study was described previously [ 3]. Background pressure during CVD was (2 ,,, 10) × 10 -5 Pa. Time of CVD was changed between 2 and 10 h which depended on the deposition temperature. The starting material was 2-methyl-l,2'-naphthyl ketone from which a graphite thin film could be obtained on Ni above 600 °C [ 1-3 ]. Ni films were prepared by the vacuum depo- sition method under 1 × 10-3 Pa either on quartz glass sub- strates (Ni/quartz) or on a-C films formed on quartz glass substrates (Ni/a-C/quartz). The substrate temperature was kept at 350"C during the Ni film depositi,m. Thickness of Ni was controlled to be between 1 /~ and 5 000 ,~, v~hich was measured by a quartz oscillator. The a-C films were formed from 1,2,5,6-dibenzanthracene under Ar flow at atmospheric pressure [ 2]. Raman scattering spectra and X-ray diffractions of the films were measured to clarify the structure. The Raman spectra were measured by backscattering method with the Ar laser light (514.5 nm) irradiating on the surface of the depos- ited film. The surface morphology of the films was observed by scanning electron microscopy (SEM). The structure of the deposit was studied also by transmission electron micros- copy (TEM), electron diffraction and energy dispersive spectrometry, which were carried out by Matsushita Tech- noresearch Inc.