Patent ID: 8734661

Claim:
A flattening method for processing a SiC or GaN surface of a workpiece, the method comprising: providing a workpiece having a surface made of SiC or GaN; using a first transporter to transport the workpiece to a first surface removal processing unit where an initial surface removal operation is performed, the initial surface removal operation including processing the surface of the workpiece by grinding, lapping, or CMP to enhance the flatness of the surface of the workpiece; after said initial surface removal operation, using the first transporter and a transport robot to transport the workpiece from the first surface removal processing unit to a cleaning unit where the surface of the workpiece is cleaned by hydrofluoric acid cleaning or pure water cleaning; using the transport robot and a second transporter to transport the workpiece from the cleaning unit to a second surface removal processing unit where a final surface removal operation for creating a damage-free, flat processed surface is performed; and after said final surface removal operation, replacing a processing solution remaining on the surface of the workpiece with pure water and then using the second transporter and the transport robot to transport the workpiece from the second surface removal processing unit to the cleaning unit where the surface of the workpiece is cleaned by at least one of SPM cleaning, aqua regia cleaning, and hydrofluoric acid cleaning, wherein the final surface removal operation is a catalyst-referred etching operation comprising (i) immersing the workpiece in a processing solution containing hydrohalic acid, hydrogen peroxide water, ozone water, or pure water, and (ii) bringing a surface of a catalyst platen into contact with or close proximity to the surface of the workpiece to process the surface, and wherein at least the surface of the catalyst platen is comprised wholly of a catalyst selected from the group consisting of platinum, gold, a ceramic solid catalyst, a transition metal, and a glass-type metal oxide.