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AssigneeInternational Business Machines Corporation
InventorsGerhard Elsner, Johann Greschner, Holger Hinkel
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A method of automatically forming identically positioned alignment marks on the front side and the back side of a silicon wafer especially prepared for use in silicon micromechanical technology. The front side and the back side of the silicon wafer are coated with an insulating layer. High-energy heavy ions are directed onto the front side insulating layer. The heavy ions penetrate the front side insulating layer, the wafer, and the back side insulating layer, thus forming single disturbed crystal lattice nuclear tracks in both insulating layers, with the wafer remaining undisturbed. The nuclear tracks in both insulating layers are etched so that corresponding identically positioned pores are opened. These pores are used as alignment marks for individual further method steps.
A method of forming identically positioned alignment marks on front and back sides of a semiconductor wafer, characterized by
A method of making alignment marks which includes
Dependencies are inferred from the claim text.