Wafer-Scale Polishing of Polycrystalline MPACVD-Diamond

Diamond offers great potential for use as a thermal spreader in various applications, including power electronics and radio-frequency (RF) applications. However, to be used an efficient spreader, the atomically smooth surface of diamond is critical bonded with chips. Herein, polishing technique 2-inch diameter wafer-scale bulk polycrystalline substrate proposed. In this work, 350 μm thick grown by microwave plasma-assisted chemical vapor deposition (MPACVD) on Si at growth rate 8 µm/h. Thereafter, three-step process was applied achieve surface, consisting grinding using slurry iron plate, ICP etching SF6 gas, final mechanical resin-bonded wheel. Surface roughness characterized atomic force microscopy showed significantly reduced from 900 nm 0.3 nm. Hence, study provide practical methods obtaining films suitable management areas RF devices.