abstract
We report the synthesis and characterization of high-quality highly <1 0 0> oriented nanocrystalline diamond (NCD) films consisting of {1 0 0} nano-facets with a high growth rate of 2.6 mu m/h. The NCD samples were grown on large (1 0 0) silicon wafers of 5.08 cm in diameter by employing CH(4)/H(2)/O(2)/N(2) chemistries without the aid of bias for orientation, microwave power 3 kW and the substrate temperature about 700 degrees C using a 5 kW-type high-power microwave plasma chemical vapor deposition (CVD) system. The strong <1 0 0> preferred orientation is unambiguously demonstrated by a detailed crystallographic texture analysis and the conventional X-ray diffraction. Moreover, a detailed morphological characterization by the high-resolution scanning electron microscopy (SEM) and the atomic force microscopy (AFM), reveal that the growth surface consists of square (1 0 0) facets with an average size of about 60 nm and has a cylindrical microstructure. We demonstrate that the root-mean-square surface roughness as low as similar to 15 nm, measured by AFM on 1 mu m(2) scan areas, can be obtained even for considerably thick (76 mu m) films. The high quality of these films is confirmed by the Raman and Fourier-transformer infrared spectra. The high-quality smooth <1 0 0>-oriented {1 0 0}-faceted NCD films may have high potential in mechanical, tribological and micro-electromechanical system (MEMS) applications. (C) 2009 Elsevier B.V. All rights reserved.
keywords
ULTRANANOCRYSTALLINE DIAMOND; THIN-FILMS; NITROGEN ADDITION; MATERIALS SCIENCE; GROWTH; CVD; MORPHOLOGY; SURFACE; NUCLEATION; OXYGEN
subject category
Crystallography; Materials Science; Physics
authors
Tang, CJ; Pereira, SMS; Fernandes, AJS; Neves, AJ; Gracio, J; Bdikin, IK; Soares, MR; Fu, LS; Gu, LP; Kholkin, AL; Carmo, MC
our authors
Andrei Kholkin
Principal Researcher
Lianshe Fu
Assistant Researcher
Maria do Rosário Teixeira Soares
Laboratory Officer
Sérgio Manuel de Sousa Pereira
Principal Researcheracknowledgements
Dr. C.J. Tang and Dr. L.S. Fu are grateful for getting funds from the Foundation of Science and Technology (FCT), Portugal.