Semiconductor Wafer Shape Evaluation via Constrained Measurement
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Solution Overview
Problem
Conventional methods for evaluating semiconductor wafers only measure the shape or assess the influence of the rear surface shape on the front surface due to vacuum suction, failing to account for shape changes during wafer processing steps, particularly in constrained and unconstrained states.
Innovation Solution
A method that acquires and compares shape data of semiconductor wafers in both unconstrained and constrained states, using suction to constrain the wafer, allowing for evaluation of shape changes and enabling feedback for improved processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional shape measurement methods are used, then the shape of the wafer can be evaluated, but the shape change of the wafer during processing steps cannot be detected
Solution Approach 1:
The invention performs preliminary shape measurement of the wafer before processing steps (such as vacuum suction) are applied. By measuring the wafer shape in advance in an unconstrained state, the system establishes a baseline that can be compared against post-processing measurements to detect shape changes that occur during manufacturing operations.
Solution Approach 2:
The invention implements a feedback mechanism where shape measurement data is acquired both before and after processing steps, and the difference between these measurements is calculated to determine shape changes. This feedback loop allows the system to identify and quantify deformation caused by specific processing operations, enabling corrective actions to be taken.
2Stability of the object's composition
If vacuum suction is applied to constrain the wafer, then the wafer can be held stable for processing, but shape deformation occurs due to the suction force
Solution Approach 1:
The invention measures the wafer shape before applying vacuum suction to establish a reference state. This preliminary measurement allows the system to distinguish between the wafer's natural shape and deformation caused by the suction process, enabling accurate detection of shape changes despite the necessary constraint for stable processing.
Solution Approach 2:
The invention uses feedback by comparing pre-suction and post-suction shape measurements to quantify the deformation caused by vacuum suction. This information can be used to adjust processing parameters or compensate for the deformation in subsequent manufacturing steps.
3Device complexity
If only front surface shape is measured, then measurement is simple, but the influence of rear surface shape and processing conditions cannot be evaluated
Solution Approach 1:
The invention uses a shape measurement device that can measure both the front surface and rear surface of the wafer, as well as perform measurements in both constrained and unconstrained states. This multi-functional capability allows comprehensive evaluation of wafer shape, processing conditions, and their interrelationships without requiring multiple separate measurement 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 the evaluation of shape changes and deformation, enhancing the quality control of wafers by predicting and minimizing external deformations and defects during processing, leading to improved manufacturing efficiency and yield.
Implementation Method 1
acquiring constrained shape data of the semiconductor wafer in a constrained state
Data Source
AI summary
A method for evaluating a shape change of a semiconductor wafer is provided. The method comprises acquiring unconstrained shape data of shape data of the semiconductor wafer being placed on a reference surface in a unconstrained state; acquiring constrained shape data of shape data of the semiconductor wafer being constrained along the reference surface in a constrained state; and comparing the unconstrained shape data and the constrained shape data. A method for manufacturing the semiconductor wafer utilizing a result of the evaluation of the wafer is also provided.