Patent ID: 6037259
Filing Date: 2000-03-14
Classification: H01L,Y10S

Abstract:
A process for forming a block (14) of characters (17) constituting a wafer I.D. on a surface (16) of a semiconductor wafer (12), comprising the following steps,selecting a region (15) on the wafer surface to receive the characters, the size of the region being on the order of the size of the block,applying a laser beam to the region in the pattern of a selected character to heat the wafer and form a hole (19), wherein the heating step causes semiconductor material from the hole to form a deposit (20) along the edge of the hole, the deposit being subject to breakage into small particles of semiconductor that can cause scratches on the surface of the wafer,then polishing the wafer in the region to separate deposit particles from the wafer surface,then cleaning the region to remove the separated deposit particles,then performing the conventional step of chemical and mechanical polishing on the wafer.