Abstract
Diamond and related materials grown have enormous potential applications due to their marvelous combination of physical and chemical properties. However, large roughness of microcrystalline diamond films makes them inapplicable in some specific applications. Recently, nanocrystalline diamond films with naturally smooth surface have been synthesized, which make low prime cost diamond wafer is possible for commercial applications. The mortification of this research is looking for a possible method to fabricate low cost and applicable diamond wafer for commercial applications. In order to achieve this goal, a suitable nucleation and growth method is necessary. In this study, a very high nucleation density (>1011 sites/cm2) and good adhesion (~ 67 mN) are achieved successfully by modified ultrasonication method and BEN method. By controlling deposition parameters, reasonable deposition rate ~ 1.3 □m/hr, and less than 50% thickness variation could be achieved for 4” wafer without substrate temperature control. With good microwave plasma reactor design and suitable substrate temperature controlling system, naturally smooth diamond film with large area (4”) uniformity is possible. Diamond layered SAW resonator and electron field emission measurements are performed successfully by using nanocrysatlline diamond films without any post-processing for demonstrating the practicability of these naturally smooth artificial diamond films. In brief, we develop a reliable and low cost processing procedure for depositing large area, uniform nanocrystalline diamond wafer with naturally smooth surface for commercial applications without expensive and time consuming post-processing.