Coordinate Measuring Machine Calibration Using Semiconductor Masks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for calibrating coordinate measuring machines in the semiconductor industry require significant conversions and the use of special masks, which are costly and impractical, especially in the clean room environment, where precise positioning is essential but often damages existing mask holders and requires enlarging the machine's dimensions.
Innovation Solution
A method involving a semiconductor production mask with multiple structures, positioned on a three-point support, rotated, and shifted to determine an overall correction function that eliminates coordinate-dependent measuring errors using a first and second correction function to align measuring parameters across different orientations and positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a calibration plate with grid points is used for self-calibration, then measurement precision is improved, but device complexity increases due to requiring multiple rotational positions and shifts
Solution Approach 1:
The patent extracts only the essential calibration features (three non-collinear points) from the complex grid plate approach, eliminating the need for multiple grid points and complex rotational positioning while maintaining calibration accuracy
Solution Approach 2:
Instead of rotating the calibration object multiple times as in prior art, the patent inverts the approach by using a statically positioned three-point support structure that defines the coordinate system directly, eliminating rotational operations
2Reliability
If the measuring table dimensions are enlarged to accommodate calibration operations, then calibration reliability is improved, but loss of substance increases due to requiring additional space
Solution Approach 1:
The patent makes the coordinate system definition dynamic by using a movable three-point support structure that can be positioned anywhere on the measuring table, eliminating the need for fixed large calibration plates and allowing calibration on the existing table area
Solution Approach 2:
The three-point support structure serves as an intermediary that transfers the coordinate system definition from the measuring table to the calibration points, enabling calibration without requiring the table itself to be enlarged or modified
3Ease of operation
If existing mask holders are used for positioning, then ease of operation is improved, but manufacturing precision deteriorates due to damage to mask holders
Solution Approach 1:
The patent uses a simple, replaceable three-point support structure that can be damaged or repositioned without affecting the expensive mask holders, effectively treating the support as a disposable or temporary component that protects the permanent fixtures
Solution Approach 2:
The positioning function is segmented into two independent parts: the permanent mask holder and the temporary three-point support, allowing the support to be adjusted or replaced without affecting the mask holder integrity
Data Source
AI summary
A method is disclosed which is suitable for the calibration of a measuring table (20) of a coordinate measuring machine (1). For this purpose, a mask (2) is deposited in a three-point support of the measuring table (20), wherein the mask (2) used for the calibration of the measuring table (20) is a mask (2), which is used for the semiconductor production. The measurement of positions of a plurality of different structures (3) which are arranged in a distributed manner on the mask (2) is carried out. The structures (3) are available in an initial orientation on the mask (2). The mask (2) is rotated and the position of the structures (3) is determined in the rotated orientation. Afterwards, the mask (2) is shifted and the position of the structures (3) is also determined. A total correction function for eliminating coordinate-dependant measuring errors is determined, wherein the total correction function has a first correction function and a second correction function.