Reflective Reticle Chuck Flatness Control via Segmented Mobile Portion
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Solution Overview
Problem
The challenge in semiconductor manufacturing is maintaining the flatness of reflective reticles, which is crucial for photolithography using shorter wavelengths, as existing technologies struggle to effectively control and improve the flatness of these reticles during the semiconductor device fabrication process.
Innovation Solution
A reflective reticle chuck with a fixed and mobile portion is used, where the mobile portion can alter the height of the securing surface relative to the fixed portion, employing a frame with elevating cells that can rise and fall independently to secure and control the flatness of the reticle, ensuring precise flatness adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional reticle chuck with a fixed securing surface is used, then the structure is simple and easy to manufacture, but the flatness of the reflective reticle cannot be controlled or improved
Solution Approach 1:
The securing surface is divided into multiple independent height-adjustable portions, each capable of being adjusted individually to correct local flatness deviations of the reticle. This segmentation allows precise control of reticle flatness by addressing specific problematic areas without affecting the entire surface uniformly.
Solution Approach 2:
The securing surface transitions from a fixed, static structure to a dynamic structure where the height of different portions can be independently adjusted. This dynamic capability enables the reticle chuck to adapt to and correct various flatness issues of the reticle by modifying the securing surface configuration in real-time.
2Manufacturing precision
If the mobile portion is used to alter the height of the securing surface to control flatness, then the flatness control capability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The height adjustment mechanism is divided into discrete, modular portions that can be independently controlled. Each portion represents a separate adjustment unit, making the overall complex function manageable through modular design and simplifying manufacturing by standardizing these adjustment modules.
Solution Approach 2:
The system controls reticle flatness by changing the height parameter of different securing surface portions independently. This parameter-based control approach allows precise flatness adjustment through controlled variation of vertical positions, enabling fine-tuned correction of reticle surface deviations.
3Productivity
If reticles with poor initial flatness are used without correction, then the manufacturing process is simpler and faster, but the yield and quality of semiconductor devices deteriorate
Solution Approach 1:
The reticle flatness is corrected in advance during the chucking process itself, before the reticle is used in photolithography. The height-adjustable securing surface pre-corrects flatness issues, eliminating the need for separate reticle re-fabrication or replacement and ensuring high-quality results from the start.
Solution Approach 2:
The system dynamically adjusts the height parameters of the securing surface to compensate for reticle flatness deviations. By changing these vertical position parameters, the system transforms reticles with poor initial flatness into effectively flat surfaces suitable for high-precision photolithography.
Data Source
AI summary
Provided are a reflective reticle chuck, a reflective illumination system including the chuck, a method of controlling the flatness of a reflective reticle using the chuck, and a method of manufacturing a semiconductor device using the chuck. The reflective reticle chuck includes a fixed portion and a mobile portion that together provide a securing surface for the reflective reticle. The mobile portion may alter a height of the securing surface relative to the fixed portion.