ELSEVIER Materials Science and Engineering A209 (1996) 68 73 MATERIAlS SCIEMCE& ElIGlMEERIMa A Enhancement of heat dissipation in well-faceted {IOO} diamond thin film S.H. Kima, Y.S. Parka, J-W. Lee, H.J. Park b , H.K. Jang b , I.S. Yangb, W.S. Yun c aNew Materials Lab., Samsung Advanced Institute of Technology, P.O. Box Ill, Suwon 440-600, South Korea bDepartment of Physics, Ehwa Woman's University, Seoul, /20-750, South Korea CDepartment of Chemistry, Seoul National University, Seoul, /51-742, South Korea Abstract We measured the surface temperature of diamond films which had different morphologies from the intensity ratio of anti-Stokes to Stokes Raman lines for each laser power. Raman spectra show that the film having {Ill} morphology (after 21 h deposition) has the best diamond quality in this work, However, the measured surface temperature of well-faceted {IOO} morphology was found to be lowest among those of any other morphologies in this work, where heating was performed by the probing laser beam itself. Furthermore, the temperature rise with increasing laser power was found to be lowest in the film with well-faceted {IOO} morphology. From these results, it can be suggested that the film with well-faceted {IOO} morphology has the highest thermal conductivity. Keywords: Heat dissipation; Diamond thin films; Thermal conductivity 1. Introduction Owing to its high thermal conductivity, about five times higher than that of copper, natural diamond has been considered to be a best candidate for thermal spreader [I]. The limitation of natural diamond for practical application has been the high cost and the difficulty in making optimum shape. Fortunately, the chemical vapor deposition (CVD) technique makes it possible to synthesize diamond as a film form [2,3] and thereby, we could resolve the problems related to the cost and the shape to some extent. Since then, the application of diamond films to the electronic devices, especially as a heat spreader, has become popular [4]. Until now, the thermal conductivity of gem-quality single crystal diamond has been regarded as the highest among those of any other materials [I]. Therefore the concentration of pure diamond in CVD diamond films has been generally accepted as the primary contributor to the value of thermal conductivity of the films. Re- cently, however, the thermal conductivity value = 26 W em - 1 K- I) of isotopically enriched CVD diamond film has been reported to be higher than that = 24-25 W em -1 K- I) of the best gem-quality single crystal diamond [5]. In addition, it has been reported that the thermal conductivity of CVD dia- mond film is anisotropic and the thermal conductivity value increases with increasing film thickness [6]. Mi- crostructure of CVD diamond films, such as point defects, dislocations and grain boundaries, was also known to affect the thermal conductivity [6]. Vandersande [7] reported that thermal conductivity value for the natural diamond with (100) rod axis was about double that with <I 10) axis under the condition of low temperature (below - 100 QC). Even though thermal conductivity study of diamond films is indis- pensible for the practical application, the reports about the effect of morphology of CVD diamond films on their thermal properties are rare up to date. In this work, we report the effect of morphology ({ 100} and {III}) on the heat dissipation of CVD diamond films, based on the micro-Raman spectroscopy measurements. 2. Experimental Diamond films were deposited on the Si substrates in a microwave-plasma-enhanced CVD (MPECVD; AS- TeX HPMM) system. Microwaves (2A5 GHz, 1000- 1300 W) were fed into a stainless-steel reaction chamber 0921-5093/96/$15.00 © 1996- Elsevier Science S.A. All rights reserved SSDI 0921-5093(95)10094-6