Patent ID: 6969687
Filing Date: 2005-11-29
Classification: H01L

Abstract:
1. A method of polishing a first material on a second material of a semiconductor die, wherein said die having a planar surface, said method comprising: forming a layer of said second material on said planar surface wherein said layer of said second material having a top surface, substantially parallel to said planar surface; forming a layer of said first material on said top surface, wherein said layer of said first material varying in a height direction above said top surface; forming a mask across the die, wherein said mask having a plurality of locations with each location having differing density of gap to pillar ratio, which is proportional to the height of said first material above said top surface; anistropically etching said first material through each gap of said mask, wherein each gap is etched by the same amount in the height direction; and polishing said first material to said top surface across the semiconductor die.