Wafer Laser Detection Layout for Tilted Clamping Jaw Alignment
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Solution Overview
Problem
Existing CMP cleaning and drying devices face challenges in accurately detecting whether a wafer is clamped by a clamping jaw and parallel to the bottom of the jaw, especially when wafers are tilted, leading to potential damage and inefficiencies due to the limitations of current laser-based detection methods.
Innovation Solution
A wafer detection device that includes a wafer parallel measuring unit emitting a parallel measuring laser beam, a wafer detecting unit emitting a wafer detecting laser beam, and a detection processing unit to determine if the wafer is clamped and parallel, using different frequencies for laser beams and reflectors to improve accuracy and reduce interference, allowing for detection regardless of wafer orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If one laser beam parallel to the wafer is used to detect whether the wafer is parallel to the bottom of the clamping jaw, then the detection is simple, but wafers tilting at particular angles may not be detected
Solution Approach 1:
The patent divides the single detection beam into multiple laser beams arranged in an array. Instead of using one beam that may miss tilted wafers, multiple beams are positioned at different locations to ensure that at least one beam intersects with the wafer regardless of its tilt angle, thereby improving detection accuracy while maintaining relatively simple system structure.
Solution Approach 2:
The patent transitions from a single-point detection approach to a multi-point detection approach by arranging laser beams in a two-dimensional array. This dimensional expansion allows the detection system to cover a broader spatial range and detect wafers with various tilt angles that would be missed by a single beam.
2Reliability
If laser sensors are installed below wafers for detection, then the detection can be performed, but cleaning liquids may drip onto such laser sensors and result in failures
Solution Approach 1:
Instead of placing the laser sensor below the wafer where it is exposed to cleaning liquids, the patent inverts the arrangement by positioning the laser sensor above the wafer. This reversal of the detection beam direction allows the sensor to remain in a clean environment while still performing effective detection of the wafer's position and orientation.
3Measurement precision
If multiple laser beams with different frequencies are used, then the detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent employs a single laser source that emits multiple frequencies simultaneously, allowing one device to perform multiple detection functions. This multi-functional approach improves detection accuracy for wafers at different orientations without requiring separate laser systems for each frequency, thereby limiting the increase in overall device complexity.
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 solution enhances the accuracy and efficiency of wafer detection, reduces breakage rates, and eliminates errors caused by cleaning liquid interference, enabling detection of wafer orientation without requiring specific wafer placement angles or orientations.
Implementation Method 1
a laser sensor, which is used for emitting a laser beam and receiving the laser beam
Data Source
AI summary
A device for detecting whether a wafer is present on a clamping jaw and detecting whether the wafer is parallel to a bottom of the clamping jaw. The device for detecting a wafer comprises: a wafer parallel measuring unit arranged in a CMP cleaning and drying device, and used for emitting a parallel measuring laser beam parallel to the bottom of the clamping jaw and receiving the parallel measuring laser beam; a wafer detection unit used for emitting a wafer detecting laser beam to the wafer and receiving the wafer detecting laser beam; and a detection processing unit electrically connected to the wafer parallel measuring unit and the wafer detection unit, and used for determining whether the wafer is present on the clamping jaw and whether the wafer is parallel to the bottom of the clamping jaw according to the received wafer detecting laser beam and parallel measuring laser beam.