Automated wafer defect inspection system and a process of performing such inspection
An automated defect inspection system has been invented and is used on patterned wafers, whole wafers, broken wafers, partial wafers, sawn wafers such as on film frames, JEDEC trays, Auer boats, die in gel or waffle packs, MCMs, etc., and is specifically intended and designed for second optical wafer inspection for such defects as metalization defects (such as scratches, voids, corrosion, and bridging), diffusion defects, passivation layer defects, scribing defects, glassivation defects, chips and cracks from sawing, solder bump defects, and bond pad area defects.
1. An automated defect inspection system, comprising:
a visual inspection device for visual inputting of a plurality of first die positions having a user defined level of quality during training and for visual inputting of a plurality of unknown quality die positions for inspection;
an illuminator for providing short pulses of light to each of the unknown quality die positions at a rate that is correlated with a rate at which the unknown quality die positions are aligned with the visual inspection device during movement relative to the visual inspection device to effectively freeze motion of the unknown quality die positions for visual inputting by the visual inspection device; and
a computer system having processing and memory capabilities for developing a model of the plurality of first die positions having the user defined level of quality and comparing the unknown quality die positions to the model to identify defects.
2. The automated defect inspection system of claim 1 , wherein the plurality of first die positions comprises a substrate selected from a group consisting of a whole patterned wafer, a sawn patterned wafer, a broken patterned wafer, at least one portion of a patterned wafer, an individual die, at least one portion of an individual die, a plurality of individual die, at least one portion of a plurality of individual die, multiple die in a waffle pak, a multi-chip module (MCM), a JEDEC tray, and an Auer boat.
3. The automated defect inspection system of claim 1 , wherein the plurality of first die positions comprises an entire die sawn from a wafer.
4. The automated defect inspection system of claim 3 , wherein the entire die sawn from the wafer is mounted on a film frame.
5. The automated defect inspection system of claim 1 , wherein the plurality of first die positions comprises a selected portion of a die sawn from a wafer.
6. The automated defect inspection system of claim 5 , wherein the die sawn from the wafer is mounted on a film frame.
7. The automated defect inspection system of claim 1 , wherein the illuminator is at least one of a brightfield illuminator positioned approximately above, a darkfield illuminator positioned approximately above, and a darkfield laser positioned approximately about a periphery of a boundary defining the plurality of first die positions.
8. The automated defect inspection system of claim 1 , wherein a number of the plurality of first die positions having the user defined level of quality that is visually inputted during developing of the model is numerically sufficient to compute a mean and a standard deviation.
9. The automated defect inspection system of claim 8 , wherein the number of the plurality of first die positions used for the model is at least twenty.
10. The automated defect inspection system claim 8 , wherein the number of the plurality of first die positions used for the model is at least thirty.
11. The automated defect inspection system claim 8 , wherein the number of the plurality of first die positions used for the model is at least 100.