Method of wafer marking for multi-layer metal processes
AssigneeChartered Semiconductor Manufacturing Ltd.
InventorsChing Thiam Chung, Kay Jin Lee
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Abstract
A new method of forming a laser mark without damage to the wafer surface is described. A pad oxide layer is formed on a silicon wafer. A nitride layer is deposited overlying the pad oxide layer. A first trench is laser cut through the nitride layer and the pad oxide layer into the silicon wafer. The trench is etched to a second depth wherein the nitride layer is used as a hard mask and wherein the trench forms an identification mark.
Claims27
A method of forming an identification mark on a silicon wafer comprising:
- providing a hard mask layer on a silicon wafer;
- laser cutting through said hard mask layer to said silicon wafer wherein a trench is formed in said silicon wafer having a first depth;
- and
- etching said trench to a second depth wherein said trench forms said identification mark.
A method of forming an identification mark on a silicon wafer comprising:
- providing a hard mask layer on a silicon wafer;
- laser cutting through said hard mask layer into said silicon wafer wherein a super soft laser mark is formed in said silicon wafer having a first depth;
- and
- etching said super soft laser mark to a second depth wherein said super soft laser mark forms said identification mark.
A method of forming an identification mark on a silicon wafer comprising:
- forming a pad oxide layer on a silicon wafer;
- depositing a nitride layer overlying said pad oxide layer;
- laser cutting through said nitride layer and said pad oxide layer into said silicon wafer wherein a trench is formed in said silicon wafer having a first depth;
- and
- etching said trench to a second depth wherein said trench forms said identification mark.
Dependencies are inferred from the claim text.