Wafer Marking Position Correction via Laser Pattern
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Solution Overview
Problem
The challenge in accurately marking semiconductor chips on a wafer is that the position of the laser beam can shift due to external disturbances like vibration or heat, necessitating a correction mechanism before the marking operation.
Innovation Solution
An apparatus and method that utilize a processing film for position correction, where a laser beam forms a pattern, and a vision camera obtains pattern position information to compare and match it with the marking position information set in the laser head, ensuring accurate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a laser beam is used for marking chips on a wafer, then marking efficiency and mass production capability are improved, but the marking position accuracy deteriorates due to external disturbances such as vibration or heat
Solution Approach 1:
The patent applies preliminary action by performing marking position correction before the actual chip marking operation. A correction pattern is formed on a processing film at the intended marking position, and its actual position is measured in advance. Based on this measurement, position correction information is calculated and stored. When actual marking is performed, the laser beam position is adjusted using this pre-calculated correction data, thereby compensating for disturbances like vibration or heat that occurred during the preliminary measurement phase.
2Area of moving object
If marking is performed on small chips (size less than or equal to 1 mm2), then device compactness and integration are improved, but the requirement for position recognition and laser emission accuracy becomes more stringent
Solution Approach 1:
The patent introduces a processing film as an intermediary object for position correction. This film contains a correction pattern that serves as a mediator between the laser beam emission system and the actual chip marking process. The correction pattern's position is measured and used to calculate correction information, which then adjusts the laser positioning for actual chip marking. This intermediary mechanism enables accurate positioning on small chips by decoupling the positioning calibration from the actual marking operation.
3Device complexity
If the laser beam emission position is assumed to be accurate during initial operation, then the device complexity is reduced, but the reliability of marking position deteriorates over time due to external disturbances
Solution Approach 1:
The patent implements feedback by measuring the actual position of the correction pattern formed on the processing film and comparing it with the intended marking position. Based on this comparison, position correction information is calculated and stored. This feedback loop allows the system to automatically compensate for position drift caused by external disturbances like vibration or heat, thereby maintaining reliable marking accuracy without requiring complex real-time active compensation systems.
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 approach allows for precise marking of semiconductor chips by measuring and correcting the marking position before the operation, ensuring accurate placement during the marking process.
Implementation Method 1
a laser head configured to emit a laser beam to the processing film for position correction to form a pattern
Implementation Method 2
a vision camera configured to obtain pattern position information
Data Source
AI summary
Provided is an apparatus and method for correcting a marking position, in which, by measuring and correcting a marking position by using a processing film for position correction, marking may be accurately performed on a position on a semiconductor chip during a marking operation, before a marking operation is performed on semiconductor chips provided on a wafer. The apparatus for correcting a marking position of a wafer includes a support configured to support a processing film for position correction, a laser head configured to emit a laser beam to the processing film for position correction to form a pattern, a vision camera configured to obtain pattern position information, a movable table configured to move the support in a horizontal direction, and a controller configured to compare and match the pattern position information and marking position information set in the laser head.