Fabrication of Very-High-Aspect-Ratio Microchannels in CVD Diamond by a Molding Technique

The growth of diamond films with built-in microchannels (through holes) of a few microns in diameter with aspect ratio up to 50 has been realized using a molding technique and a special template. The method employs the microwave plasma assisted diamond deposition on (III) Si substrate with regular Si whiskers followed by separation of diamond from the substrate to obtain replica of the original pattern. The holes are hexagonal in cross section, and the hole "diameter" is almost constant over the whole depth (ca. 100 μm) The position, diameter and depth of the microchannels can be varied in a broad range. Possible applications of perforated diamond film include membranes, drawing dies, heat spreaders with interconnections for electronic circuits, and novel types of diamond-based composites.