Wafer Table Chuck Particle Recess Alignment
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Solution Overview
Problem
Misalignment errors during the manufacturing of integrated circuits, caused by particles becoming trapped between the chuck and the workpiece, lead to theta errors and non-correctable errors, affecting the accuracy of patterned layers and device yield.
Innovation Solution
A chuck with particle recesses is designed to accommodate errant particles, maintaining the parallelism between the chuck and the workpiece, thereby reducing alignment shifts and errors by trapping particles underneath alignment marks, ensuring the chuck and workpiece remain substantially parallel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a particle becomes trapped between the chuck and the workpiece, then the particle causes alignment errors and theta errors, but the focal range deteriorates and manufacturing precision decreases
Solution Approach 1:
The patent converts the harmful effect of trapped particles into a beneficial outcome by designing particle recesses that intentionally accommodate particles. Instead of allowing particles to cause alignment errors on the workpiece surface, the recesses capture particles in designated areas, transforming the harmful presence of particles into a controlled situation that prevents misalignment and maintains manufacturing precision.
Solution Approach 2:
The particle recess acts as an intermediary structure between the chuck and the workpiece. It provides a dedicated space for particles to reside, mediating the interaction between the two surfaces and preventing direct particle-induced misalignment. The recess serves as a buffer zone that absorbs the harmful effect of particle contamination.
2Manufacturing precision
If the chuck surface is made flat to improve alignment, then manufacturing precision improves, but particles trapped on the surface cause theta errors
Solution Approach 1:
The chuck surface is designed with local quality variations: most of the surface remains flat for optimal alignment, while specific localized regions contain particle recesses. This allows the majority of the surface to maintain high manufacturing precision while the localized recesses handle particle accommodation, preventing theta errors without compromising overall alignment quality.
Solution Approach 2:
The chuck surface is segmented into functional zones: flat alignment-critical areas and recessed particle-accommodation areas. This segmentation allows different regions to serve different purposes - the flat surfaces maintain precision while the recessed surfaces trap particles, resolving the contradiction between flatness and particle resistance.
3Productivity
If particles are allowed to settle on the chuck surface, then device yield decreases due to misalignment, but creating particle recesses increases device complexity
Solution Approach 1:
The chuck incorporates a porous or recessed surface structure with particle recesses that allow particles to settle into designated cavities. This porous-like structure increases device yield by preventing particle-induced misalignment while adding minimal complexity - the recesses are simple geometric features integrated into the existing chuck design rather than complex additional mechanisms.
Data Source
AI summary
An apparatus for a chuck having particle recesses is provided. In some embodiments, the chuck includes a plurality of impressions and a particle recess. The impressions of the plurality of impressions are laterally spaced and extend into the chuck from a top surface of the chuck to a base surface of the chuck. The base surface of the chuck defines bottom surfaces respectively of the impressions and is spaced between the top surface of the chuck and a bottom surface of the chuck. The particle recess extends in to the chuck from the top surface of the chuck to a location spaced between the base surface of the chuck and the bottom surface of the chuck. In particular, the particle recess is configured to underlie a workpiece alignment mark of a workpiece.