Semiconductor Bump Height Measurement via Liquid Meniscus Reference
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Solution Overview
Problem
Current semiconductor inspection devices that measure the height of surface structures like bumps require lengthy processes, often taking hours to measure multiple bumps due to the need to detect reflected light by shifting focal positions, which is inefficient for large-scale semiconductor manufacturing.
Innovation Solution
An inspection device that uses a stage, seal ring, liquid nozzle, camera, and arithmetic operation unit to determine the height of bumps by supplying a liquid to reach a predetermined height, allowing the bumps to protrude and be imaged, with the arithmetic unit calculating the exposed area to determine the height based on pixel count, significantly reducing measurement time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods (confocal system, triangulation system, white interference system) are used to measure bump heights, then measurement precision is maintained, but inspection time becomes excessively long
Solution Approach 1:
The patent replaces optical focusing mechanisms with a liquid meniscus reference system. Instead of mechanically or optically adjusting focal positions to measure bump heights, the invention uses a liquid bridge formed between a nozzle and substrate to create a stable reference plane. The bump height is determined by comparing the bump top position relative to the liquid meniscus curvature, eliminating the need for repeated focal position adjustments and enabling rapid measurement while maintaining precision.
2Measurement precision
If focal position shifting is required to detect reflected light, then measurement accuracy is achieved, but productivity decreases
Solution Approach 1:
The invention substitutes the mechanical/optical focal adjustment system with a liquid reference plane system. A nozzle supplies liquid to form a meniscus between the nozzle tip and substrate surface. The liquid meniscus provides a stable reference plane that eliminates the need for focal position shifting. Bump heights are measured by detecting the position of bump tops relative to the liquid meniscus curvature, enabling high-speed measurement that maintains accuracy while dramatically improving productivity.
3Loss of information
If multiple focal positions are scanned to measure heights, then comprehensive measurement data is obtained, but inspection time increases
Solution Approach 1:
The patent replaces multi-position focal scanning with a single-plane liquid meniscus reference method. The liquid bridge formed between nozzle and substrate creates a stable reference plane that allows all bump height measurements to be taken simultaneously from one imaging plane. The arithmetic operator calculates bump heights by comparing bump top positions to the liquid meniscus curvature, obtaining complete measurement data without time-consuming focal position scanning.
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 allows for rapid height determination of multiple bumps in approximately five minutes, reducing overall inspection time and improving efficiency in semiconductor manufacturing by eliminating the need to change focal positions and shift imaging positions.
Implementation Method 1
a liquid supply unit configured to supply a liquid on the substrate to reach a first height that allows a portion of the protrusion feature of the substrate to be exposed
Data Source
AI summary
According to one embodiment, an inspection device includes a stage on which a substrate having a protrusion portion on a surface thereof is mountable. A ring member presses an outer periphery of the substrate on the stage. A liquid supply unit supplies a liquid on the surface of the substrate from the surface thereof to a first height. An imaging unit captures an image of a surface of the liquid and the protrusion portion from above the surface of the substrate. An arithmetic operation unit determines a size of an exposed portion of the protrusion portion which is exposed from the surface of the liquid by using the image obtained from the imaging unit, and determines a height of the protrusion portion on the basis of the size of the exposed portion.