Multi-analyzer Ellipsometry for Wafer Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ellipsometry tools lack stability in measurements, which affects the accuracy of dielectric property analysis for thin polished plates like silicon wafers.
Innovation Solution
An ellipsometry system that uses a rotatable analyzer with multiple discrete angular positions to collect and process spectrum data, allowing for simultaneous regression analysis to improve measurement stability and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional single-angle ellipsometry is used, then the device complexity is low, but measurement stability and precision are insufficient
Solution Approach 1:
The analyzer is segmented into multiple discrete angular positions (e.g., 0°, 45°, 90°, 135°) rather than using a continuous single-angle configuration. This segmentation allows the system to collect ellipsometry data at multiple predetermined angles, improving measurement stability and precision by reducing systematic errors while maintaining manageable device complexity through discrete positioning.
Solution Approach 2:
The measurement approach transitions from a single-angle (one-dimensional) configuration to a multi-angle (multi-dimensional) configuration. By introducing the angular dimension as a variable with multiple discrete values, the system captures additional information about the sample's dielectric properties, thereby improving reliability and precision without proportionally increasing complexity.
2Measurement precision
If multi-angle spectrum data collection is implemented, then measurement precision improves, but data processing complexity increases
Solution Approach 1:
Spectrum data collected at multiple discrete angular positions are merged and processed simultaneously through regression analysis. The processor module integrates the multi-angle spectrum data and performs simultaneous regression to extract dielectric properties, achieving improved precision by combining information from multiple angles while managing processing complexity through unified analysis.
Solution Approach 2:
The system employs regression analysis that can incorporate feedback mechanisms to refine the extraction of dielectric properties. By analyzing the relationship between the multi-angle spectrum data and the sample properties, the system iteratively improves the precision of the measured parameters, effectively managing the complexity through intelligent processing algorithms.
3Reliability
If multiple discrete angular positions are used, then systematic errors are minimized, but the measurement time increases
Solution Approach 1:
The analyzer is configured with predetermined discrete angular positions (e.g., 0°, 45°, 90°, 135°) that are pre-calibrated and ready for measurement. This preliminary configuration of optimal angles allows the system to quickly transition between measurement positions without time-consuming adjustments, minimizing systematic errors while reducing the time penalty of multi-angle measurement through efficient pre-planned positioning.
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 system achieves enhanced stability and precision in dielectric property analysis by minimizing systematic errors and improving the sensitivity of measurements for wafer inspection.
Implementation Method 1
an analyzer configured for polarizing the reflected beam. The polarization direction of the analyzer may be rotatable to a plurality of predetermined, discrete angular positions
Implementation Method 2
an illumination source configured for delivering an incident beam towards the wafer. The incident beam may reflect off the wafer thereby forming a reflected beam
Implementation Method 3
A detector may be utilized to collect a set of spectrum data based on the reflected beam passing through the analyzer
Data Source
AI summary
Ellipsometry systems and ellipsometry data collection methods with improved stabilities are disclosed. In accordance with the present disclosure, multiple predetermined, discrete analyzer angles are utilized to collect ellipsometry data for a single measurement, and data regression is performed based on the ellipsometry data collected at these predetermined, discrete analyzer angles. Utilizing multiple discrete analyzer angles for a single measurement improves the stability of the ellipsometry system.