Patent ID: 7195545
Filing Date: 2007-03-27
Classification: B24B,H01L

Abstract:
1. A method of chamfering a nitride semiconductor wafer comprising the steps of: preparing a soft whetting apparatus having a long continually-fed elastic tape and whetting granules of #300 to #5000 implanted on the elastic tape; bringing the elastic tape into angular inscribing contact with an edge of the circular nitride wafer with an angular contact angle of 40 degrees to 90 degrees at a pressure; supplying the elastic tape with a whetting liquid which is powderless water, powderless oil, powder including water, or powder including oil; rotating the nitride wafer in the inscribing contact with the elastic tape; feeding the elastic tape at a constant speed or varying speeds of 5 mm/min to 60 mm/min in the angular direction around the wafer edge; and abrading the edge of the wafer by the granules implanted on the soft elastic tape into edge roughness of Ra 5 μm to Ra 10 nm, wherein the chamfering method includes three steps, a first step uses a whettape of #300 to #1000, a second step uses another whettape of #1000 to #2500 and a third step uses another whettape of #2500 to #5000.