Substrate Lifting Apparatus Thermal Expansion Compensation
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Solution Overview
Problem
Semiconductor substrate processing apparatuses face challenges in minimizing substrate deformation due to thermal expansion issues during heat-related processes, particularly when using electrostatic chucks and substrate lifting mechanisms.
Innovation Solution
A substrate lifting apparatus comprising a combination of upper and lower plates with different thermal expansion coefficients, kinematically coupled connecting portions, and a driving unit, where the upper plate has a lower thermal expansion coefficient and includes magnets for alignment, and pins that contact the substrate, reducing deformation by managing thermal expansion through specific geometric and material design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a substrate lifting apparatus is used to raise and lower the substrate, then substrate transfer capability is improved, but thermal expansion causes deformation and positioning errors
Solution Approach 1:
The patent applies the thermal expansion principle by using a lower plate with higher thermal expansion coefficient than the upper plate. When heated, the lower plate expands more than the upper plate, creating a compensatory effect that reduces overall thermal deformation of the substrate lifting apparatus, thereby maintaining positioning accuracy during substrate transfer operations
Solution Approach 2:
The patent uses composite materials with different thermal expansion coefficients for the upper and lower plates. This composite structure allows the system to leverage the differential expansion properties of the materials to counteract thermal deformation, ensuring both substrate transfer capability and positioning precision are maintained
2Ease of manufacture
If the upper plate and lower plate are made of the same material, then manufacturing simplicity is improved, but thermal expansion causes misalignment between connecting portions
Solution Approach 1:
The patent deliberately selects materials with different thermal expansion coefficients for the upper and lower plates. The lower plate's higher expansion coefficient compensates for thermal contraction in the upper plate, maintaining alignment of the connecting portions during thermal cycles and preventing misalignment despite using different materials
Solution Approach 2:
The patent applies local quality by assigning different material properties to different parts of the system. The lower plate uses a material with higher thermal expansion coefficient while the upper plate uses a material with lower expansion coefficient, optimizing each component's thermal response to maintain overall alignment and functionality
3Strength
If rigid connecting portions are used between upper and lower plates, then structural strength is improved, but thermal expansion causes stress and potential damage
Solution Approach 1:
The patent changes the thermal expansion parameter by selecting materials with different expansion coefficients for the upper and lower plates. This parameter change allows the rigid connecting portions to maintain structural strength while the differential expansion absorbs thermal stress, preventing damage during temperature variations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively minimizes substrate deformation by controlling thermal expansion, ensuring precise and stable substrate handling during processing, thereby enhancing the reliability and accuracy of semiconductor manufacturing processes.
Implementation Method 1
the upper plate includes an upper magnet on the lower surface, and the lower plate includes a lower magnet aligned with the upper magnet on the upper surface
Data Source
AI summary
A substrate lifting apparatus and a substrate processing apparatus for reducing deformation due to heat are provided. The substrate lifting apparatus comprises a plurality of pins in contact with a substrate, an upper plate for supporting the plurality of pins and having a plurality of upper connecting portions formed on a lower surface, a lower plate having a plurality of lower connecting portions connected to the plurality of upper connecting portions formed on an upper surface and disposed under the upper plate, and a driving unit for driving the plurality of pins to move up and down, wherein the lower plate supports a plurality of bushes and a plurality of shafts passing through the plurality of bushes on an upper surface thereof.