Substrate Form Change Measurement via Multi-Beam Optical Imaging
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Solution Overview
Problem
In the semiconductor industry, precise alignment and bonding of wafers are challenged by distortions that occur during the bonding process, leading to deviations in alignment precision, which existing measurement devices struggle to accurately and efficiently detect, especially due to the complexity and cost associated with measuring changes in shape parallel to the substrate surface.
Innovation Solution
A mechanical-optical measurement system using optics and detection means to determine relative shifts between structures on a substrate surface without relying on an absolute reference system, allowing for simultaneous measurement of multiple positions and detection of changes caused by substrate treatment, utilizing CCD detectors or analog cameras for high precision and economic measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing measurement devices traverse two surfaces with respect to a coordinate system defined in a fixed manner to measure structure positions, then measurement can be performed, but the measurement complexity and costs increase significantly
Solution Approach 1:
The measurement task is segmented into multiple independent optics apparatus, each capturing a specific field of view. Instead of using one complex traversing measurement device, multiple simpler optics units work in parallel to capture different regions of the substrate surface, reducing individual device complexity while maintaining overall measurement precision
Solution Approach 2:
The invention uses optical copying to create images of structures on the substrate surface. By capturing optical images rather than performing direct physical measurements, the system avoids complex mechanical traversing devices and achieves precise alignment measurement through image analysis and coordinate transformation
2Measurement precision
If measurement devices traverse surfaces to measure structure positions before and after bonding, then distortion information can be obtained, but the measurement time and productivity decrease
Solution Approach 1:
The measurement system captures images of structures at multiple positions simultaneously before bonding occurs. By recording the initial positions of all structures in advance across multiple fields of view, the system eliminates the need for repeated traversing measurements after bonding, significantly reducing total measurement time while maintaining distortion measurement accuracy
Solution Approach 2:
Multiple optics apparatus are merged into a coordinated measurement system that captures data from different substrate regions simultaneously. The combined data from all optics units provides complete distortion information in a single measurement cycle, eliminating sequential traversing and improving productivity
3Ease of operation
If absolute reference systems are used for measuring structure positions, then coordinate measurement is simplified, but the ability to detect relative shifts caused by substrate deformation decreases
Solution Approach 1:
Instead of using a fixed absolute reference system, the invention inverts the approach by using the structures themselves on the substrate as reference points. The measurement system determines positions relative to these substrate-mounted structures, allowing automatic compensation for substrate deformation and enabling accurate detection of relative shifts while maintaining operational simplicity
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
Enables prompt, precise, and reliable determination of changes in substrate shape, providing statistical information for improved alignment accuracy and potential in-situ measurement during bonding processes, allowing for the detection of shifts as small as less than 50 nm, thereby addressing the limitations of existing measurement methods.
Implementation Method 1
with a first optics apparatus (4) having a first beam path (12) and a second optics apparatus (7) having a second beam path (13), wherein the first beam path (12) is directed onto the first structure (14) and the second beam path (13) is directed onto the second structure (15)
Data Source
AI summary
The present invention relates to a device and method for determining changes in the shape of a substrate parallel to its substrate surface. The device comprisesat least one detection apparatus for detecting images of structures which are located on the substrate surface, andoptics comprised of at least two optics apparatus with at least two different beam paths for imaging of the structures on the detection apparatus.The device is able to determine distances (dx1, dy1, dx2, dy2, dxn, dyn) of images of the structures and/or changes of the distances (dx1, dy1, dx2, dy2, dxn, dyn).