Patent ID: 7338909
Filing Date: 2008-03-04
Classification: H01L

Abstract:
1. A method for locally etching a semiconductor wafer mark area comprising the steps of: providing a semiconductor wafer comprising a process surface including an alignment mark area comprising readable alignment marks; depositing a material layer according to a semiconductor device fabrication process over the process surface; and, selectively applying a wet etchant to the alignment mark area to the exclusion of a surrounding area to selectively etch the material layer overlying the alignment mark area to reproduce readable alignment marks, said step of applying comprising using an applicator tip having a distal tip portion formed of a plastic material, said distal tip portion comprising a surface for holding a droplet of wet etchant without absorbing said wet etchant, said droplet attached to said surface according to a surface tension of said surface, said surface comprising a geometry selected from the group consisting of a positive radius of curvature, a negative radius of curvature, and a cone shaped cavity.