The Growth of Diamond Films on Porous Anodic Alumina

Chemical vapor deposition (CVD) diamond and Porous anodic alumina (PAA) are important materials that have been attracting great scientific and technological interest. This is due mainly to the novel properties of each these materials and to possible applications in several areas. The searches for the improvement of these materials have naturally been made separately. It will evoke great effect on several future applications if such materials can be structured together. PAA, which is formed by anodization of aluminum in acidic solution, is a typical self-ordered nanohole-array material. Its structure can be described as compact barrier layer directly attaching to aluminum substrate and located over it porous layer, made of a close-packed array of columnar cells, each containing fine, regular, almost cylindrical, parallel-sided, central axial pores. Diamond is one of the most technologically advanced materials available today. It has a unique combination of excellent physical and chemical properties, which makes it ideal for numerous potential applications. Diamond deposition on PAA was carried out in a hot filament chemical vapor deposition (HFCVD) system. PAA was used as substrate and tungsten wire as the filament. The conventional gas mixture of methane and hydrogen was used as the reaction source gas. The effects of deposition parameters on PAA are investigated. The diamond/PAA composite were analyzed by Raman spectroscopy and the morphology was characterized by scanning electron microscopy (SEM), which are commonly used to identify the quality of diamond films. The results indicated that the homogeneous and dense diamond film could be obtained by HFCVD method on PAA.