Metrology Apparatus Sensitivity Adjustment for Overlay Accuracy
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Solution Overview
Problem
The increasing complexity and miniaturization of semiconductor devices require more stringent accuracy in overlay and critical dimension measurements during the patterning process, as errors can lead to functional failures and electrical issues, necessitating a method to characterize and adjust metrology apparatus settings effectively.
Innovation Solution
A metrology apparatus that applies an incident radiation beam to a substrate with features of different layers, receives intensity data, and determines adjustments based on the difference between initial and measured parameter values, allowing for precise adjustments to improve overlay and critical dimension accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dimensions of functional elements are reduced and the amount of functional elements is increased, then the productivity and device functionality are improved, but the measurement precision and manufacturing precision deteriorate due to more stringent accuracy requirements
Solution Approach 1:
The patent changes the operational parameters of the metrology apparatus based on measured process parameters. Specifically, it adjusts characteristics such as illumination conditions, detection sensitivity, or measurement methodology parameters according to the actual process state, enabling the system to adapt to different measurement requirements for various feature sizes and densities
Solution Approach 2:
The patent implements a feedback loop where process parameters are measured, compared against target values, and used to determine adjustments to metrology apparatus characteristics. This closed-loop system continuously optimizes measurement precision by adjusting apparatus parameters based on actual process performance data
2Manufacturing precision
If the accuracy requirements for overlay and critical dimension become more stringent, then the manufacturing precision is improved, but the device complexity increases due to the need for sophisticated adjustment mechanisms
Solution Approach 1:
The patent enables the metrology apparatus to automatically adjust its own operational characteristics based on measured process data. The system self-regulates by using process parameter measurements to determine and apply appropriate adjustments to its measurement characteristics, reducing the need for external intervention or complex manual adjustment mechanisms
Solution Approach 2:
The patent dynamically changes the operational parameters of the metrology apparatus based on measured process conditions. By adjusting parameters such as illumination wavelength, numerical aperture, or detection sensitivity in response to actual process variations, the system achieves high manufacturing precision without requiring permanently complex hardware configurations
3Ease of operation
If the metrology apparatus operates with fixed characteristics, then the ease of operation is improved, but the adaptability deteriorates when process conditions vary
Solution Approach 1:
The patent transforms the metrology apparatus from a static system with fixed characteristics to a dynamic system that automatically adjusts its operational parameters. The apparatus continuously adapts its measurement characteristics based on real-time process data, maintaining both ease of operation and high adaptability to varying process conditions
Solution Approach 2:
The patent implements automatic parameter adjustment by changing the operational characteristics of the metrology apparatus based on measured process parameters. This allows the system to adapt to different process conditions while maintaining simple operation, as the adjustment process is automated and based on objective measurements rather than manual intervention
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 enables precise characterization and adjustment of metrology apparatus settings, reducing errors and improving the accuracy of overlay and critical dimension measurements, thereby enhancing the reliability of semiconductor devices.
Implementation Method 1
receiving first intensity data representing first intensity of a first portion of the incident radiation beam scattered by the first features and the second features
Data Source
AI summary
A method is described herein including applying, by a metrology apparatus, an incident radiation beam to a substrate including first features on a first layer and second features on a second layer, a relationship between the first and second features being characterized by a parameter of interest having a first value, wherein the metrology apparatus is operated in accordance with at least one characteristic having a first setting; receiving intensity data representing intensity of a portion of the incident radiation beam scattered by the first and second features; determining, based on the intensity data, a second value of the parameter of interest; and applying one or more adjustments to the at least one characteristic such that the at least one characteristic has a second setting different from the first, the one or more adjustments being determined based on a difference between the first value and the second value.