Fluorescent Alignment Marks for Accurate Wafer Bonding
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Solution Overview
Problem
The scaling down of semiconductor devices poses challenges in achieving improved quality, yield, performance, and reliability due to issues during the fabrication process, particularly in aligning wafers effectively during bonding.
Innovation Solution
The integration of fluorescence material-based alignment marks on semiconductor devices, which are arranged parallel to each other on both wafers, enhances optical recognition and serves as complementary references during bonding, improving the yield and reliability of the semiconductor device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional alignment marks are used during wafer bonding, then the fabrication process can proceed, but optical recognition is insufficient leading to poor alignment precision
Solution Approach 1:
The patent applies fluorescence material to alignment marks that emit light at specific wavelengths when excited. This causes the alignment marks to glow with distinct colors or brightness levels, making them easily distinguishable under optical microscopes during wafer bonding. The fluorescent properties enhance the contrast and visibility of alignment marks, directly improving optical recognition and alignment precision without adding mechanical complexity.
2Productivity
If wafer scaling is continued to improve device density, then computing ability increases, but alignment and bonding issues worsen
Solution Approach 1:
The patent introduces fluorescence material as an intermediary enhancement layer applied to alignment marks on the wafer surface. This fluorescent coating acts as a mediator that amplifies the optical signal from the alignment marks, allowing precise detection and alignment even as device features scale down. The fluorescent intermediary enables the alignment system to maintain precision despite the reduced scale of underlying device structures.
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 use of fluorescence material in alignment marks improves optical recognition and bonding accuracy, leading to enhanced yield and reliability of semiconductor devices by ensuring precise alignment and bonding processes.
Implementation Method 1
The plurality of first alignment marks and the plurality of second alignment marks comprise a fluorescence material
Data Source
AI summary
The present application discloses a method for fabricating a semiconductor device with integrated decoupling alignment features. The method includes providing a first substrate; forming a plurality of first alignment marks on the first substrate and parallel to each other, wherein the first substrate and the plurality of first alignment marks together configure a first wafer; providing a second wafer comprising a plurality of second alignment marks parallel to each other; and bonding the second wafer onto the first wafer. The plurality of second alignment marks are arranged parallel to the plurality of first alignment marks and adjacent to the plurality of first alignment marks in a top-view perspective. The plurality of first alignment marks and the plurality of second alignment marks comprise a fluorescence material.