Automatic kerf offset mapping and correction system for laser dicing
Embodiments of the present disclosure include methods of determining scribing offsets in a hybrid laser scribing and plasma dicing process. In an embodiment, the method comprises forming a mask above a semiconductor wafer. In an embodiment, the semiconductor wafer comprises a plurality of dies separated from each other by streets. In an embodiment, the method further comprises patterning the mask and the semiconductor wafer with a laser scribing process. In an embodiment, the patterning provides openings in the streets. In an embodiment, the method further comprises removing the mask, and measuring scribing offsets of the openings relative to the streets.
1. A method of determining scribing offsets, comprising:
forming a mask above a semiconductor wafer, wherein the semiconductor wafer comprises a plurality of dies separated from each other by streets;
patterning the mask and the semiconductor wafer with a laser scribing process, wherein the patterning provides openings in the streets, wherein one or more of the openings comprises an S-shaped pattern;
removing the mask;
subsequent to removing the mask, measuring scribing offsets of the openings relative to the streets by measuring an offset at a plurality of locations along the S-shaped pattern and determining an average offset, the average offset including both a translational offset and an angular offset; and
using the average offset as an offset correction for processing a subsequent semiconductor wafer.
2. The method of claim 1 , wherein measuring the scribing offsets comprises measuring an offset of all of the openings on the semiconductor wafer.
3. The method of claim 1 , further comprising:
calculating an offset correction; and
storing the offset correction.
4. The method of claim 3 , wherein the offset correction is used to update a wafer map used in scribing processes of subsequent semiconductor wafers.
5. The method of claim 1 , wherein the semiconductor wafer is a production wafer.
6. The method of claim 1 , wherein the semiconductor wafer is a short-loop wafer.
7. The method of claim 6 , wherein the short-loop wafer comprises bumping and die dimensions that are the same as a production wafer.
8. A method of singulating a semiconductor wafer, comprising:
determining an offset correction by laser scribing a first semiconductor wafer having a first mask thereon, the laser scribing forming one or more of the openings having an S-shaped pattern, and measuring scribing offsets in the first semiconductor wafer subsequent to removing the first mask by measuring an offset at a plurality of locations along the S-shaped pattern and determining an average offset, the average offset including both a translational offset and an angular offset;
forming a second mask above a second semiconductor wafer, wherein the second semiconductor wafer comprises a plurality of dies separated from each other by streets; and
patterning the second mask and second semiconductor wafer with a laser scribing process that utilizes a wafer map that has integrated the offset correction, wherein the patterning provides openings through the second mask and into the streets of the second semiconductor wafer.
9. The method of claim 8 , wherein the laser scribing process singulates the dies of the second semiconductor wafer.
10. The method of claim 8 , further comprising:
plasma etching the second semiconductor wafer through the openings, wherein the plasma etching singulates the dies of the second semiconductor wafer.