Semiconductor Wafer Cutting Groove Position Detection
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Solution Overview
Problem
The challenge is to accurately detect the position of a cut groove overlapping with a laser-processed groove during the cutting of semiconductor wafers, as existing methods struggle to differentiate between the two, leading to potential damage from position deviations.
Innovation Solution
A cutting method that forms a half-cut groove with a reflective bottom in the peripheral surplus region, using epi-illumination to distinguish it from the laser-processed groove, allowing for accurate detection and correction of position deviations before cutting, ensuring precise alignment of the cutting blade with the laser-processed groove.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser-processed grooves are formed to prevent Low-k film separation, then film separation is prevented, but it becomes very difficult to detect the position of cut grooves overlapping with laser-processed grooves
Solution Approach 1:
The invention uses optical reflection differences to create visual contrast between laser-processed grooves and cut grooves. The laser-processed groove bottom diffusely reflects light and appears dark, while the cut groove bottom specularly reflects light and appears bright, enabling easy detection and discrimination of groove positions
Solution Approach 2:
The invention creates a visual copy or representation of the groove positions through optical reflection patterns. By using epi-illumination to make the grooves visible with distinct brightness patterns, the system creates an optical map that allows detection and measurement of groove positions without direct physical contact
2Productivity
If cutting is performed along laser-processed grooves, then workpiece division is achieved, but position deviation between grooves causes device damage
Solution Approach 1:
The invention implements a feedback mechanism by detecting the actual positions of laser-processed grooves and cut grooves through optical reflection patterns, calculating position deviations, and correcting the cutting blade positioning accordingly. This closed-loop control ensures accurate alignment and prevents device damage
Solution Approach 2:
The invention performs preliminary detection and correction of position deviations between grooves before the actual cutting operation. By measuring groove positions and correcting alignment in advance, the system ensures accurate cutting blade positioning and prevents harmful position deviations during cutting
3Manufacturing precision
If the cut groove position is accurately controlled to overlap with the laser-processed groove, then film separation is prevented, but detection of the cut groove position becomes extremely difficult
Solution Approach 1:
The invention uses optical reflection characteristics to create distinct visual signatures for different groove types. The cut groove's specular reflection appears bright while the laser-processed groove's diffuse reflection appears dark, enabling easy detection and confirmation of accurate groove overlap without compromising manufacturing precision
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 enables accurate detection and correction of position deviations, preventing damage to devices by ensuring the cutting blade is positioned at the center of the laser-processed groove, thereby facilitating precise cutting of semiconductor wafers without damaging the functional Low-k film.
Implementation Method 1
a detection step of photographing the half-cut groove by the photographic unit and detecting the half-cut groove with discrimination from the laser-processed groove that diffusely reflects the light of the epi-illumination part
Implementation Method 2
laser-processed grooves are formed in the planned dividing lines by irradiation with a laser beam
Data Source
AI summary
In a cutting method of a workpiece, a half-cut groove having a groove bottom that reflects light of an epi-illumination part is formed in a range of a peripheral surplus region of a planned dividing line that has not been cut, and the half-cut groove is detected with discrimination from a laser-processed groove that diffusely reflects the light and is darkly displayed.