Segmented Substrate Holding Surface for Warpage Compensation
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Solution Overview
Problem
Existing substrate holding methods for circular substrates, particularly in semiconductor manufacturing, face challenges in reliably attracting and holding substrates that are prone to warping due to increased size and decreased thickness, leading to potential misalignment during probe inspection.
Innovation Solution
A substrate holding method and apparatus that divide the substrate holding surface into multiple regions, allowing sequential suction and pressure application using a gas ejection unit to maintain the substrate's position, with leakage detection to ensure secure holding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If concentric grooves are used to suck the substrate, then the substrate can be held on the stage, but sufficient attraction force is not obtained when leakage occurs due to substrate warpage
Solution Approach 1:
The substrate holding surface is divided into multiple independent suction regions (first suction region, second suction region, third suction region) that can operate independently. When leakage occurs in one region due to substrate warpage, the other regions can still provide sufficient attraction force to hold the substrate securely.
2Area of stationary object
If the substrate size is scaled up and thickness is decreased, then more substrate area can be processed, but the substrate becomes easily warped
Solution Approach 1:
The holding surface is segmented into multiple suction regions that can independently adapt to substrate shape variations. This allows the system to maintain effective holding of large-area substrates even when they warp, as each region can compensate for local shape deviations.
Solution Approach 2:
Different suction regions can apply different suction pressures tailored to local substrate conditions. Regions experiencing leakage or warpage can be compensated by adjusting the suction pressure in that specific region while maintaining normal operation in other regions.
3Device complexity
If a single suction region is used, then the device structure is simple, but leakage at one position causes insufficient holding
Solution Approach 1:
The suction system is divided into multiple independent regions (first, second, and third suction regions) that can function independently. This segmentation ensures that leakage in one region does not compromise the overall holding reliability, as other regions continue to provide secure attachment.
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
This method effectively attracts and holds substrates with significant warpage, preventing misalignment and ensuring reliable probe inspection by distributing suction pressure evenly and detecting leakage.
Implementation Method 1
the substrate can be sucked by forming a plurality of grooves concentrically in a substrate holding surface of a stage and decreasing a pressure in the grooves
Implementation Method 2
the pressing unit may be a gas ejection unit for ejecting a gas toward a top surface of the sucked portion
Data Source
Figure 1
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AI summary
Fine suction grooves 7b for sucking a wafer W are provided in a holding surface 7a of a stage 7. The suction grooves 7b are divided into, for instance, nine suction regions 61A to 61I. The suction region 61I sucks a center portion of the circular wafer w. The suction regions 61A, 61B, 61C, 61D, 61E, 61F, 61F and 61H suck a peripheral end portion of the circular wafer W. A gas is separately jetted to nine positions on the wafer W held by the stage 7, said nine positions corresponding to the suction regions 61A to 61I.