I-2-3 Nitride Semiconductor Device Applications of Diamond Substrate : Diamond Substrate Planarization Polishing Technique

A heat sink with high thermal conductivity is very important part to achieve high efficient and stablenitride semi conductors,such as an optical device for short wavelength laser.Diamond is one of the candidate materials for extremely high thermal conductive heat sink.However,it is difficult to make the diamondsubstrate surface flat in order to obtain a good contact with the laser chip.This paper focuses on a polish ingcharacteristics in terms of crystal orientation on(100) face.As a result,the highest polishing rate is achieved when the polishing direction is in parallel to the <100> crystal orientation.0n the other hand,the lowestpolishing rate but the smoothest surface is obtained in case of the<110>crystal orientation.