Spatial OES Collimator Layout for In-Situ Etch Uniformity
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Solution Overview
Problem
Existing methods for monitoring etch uniformity in plasma etch processes lack effective in-situ feedback, particularly regarding spatial variations, leading to inefficiencies in developing and optimizing etch recipes.
Innovation Solution
A spatial optical emission spectroscopy (OES) system with multiple collimators and a guide to sample OES signals from various locations within an etch chamber, coupled with an etch uniformity monitoring sub-system to analyze and optimize etch recipes using machine learning techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spatial OES sampling with multiple collimators is implemented, then measurement precision of etch uniformity is improved, but device complexity increases
Solution Approach 1:
The etch chamber monitoring system is segmented into multiple independent collimators, each responsible for sampling OES signals from a specific spatial location. This segmentation enables precise spatial-resolved measurement of etch uniformity across different regions of the wafer, directly improving measurement precision while managing complexity through modular design
Solution Approach 2:
A guide structure is introduced as an intermediary component to route and organize the multiple collimators. The guide mediates between the complex arrangement of multiple collimators and the etch chamber environment, providing structural support and optical path alignment without requiring complex external mounting mechanisms
2Productivity
If in-situ OES signal sampling is performed during etch process, then productivity of etch recipe development is improved, but device complexity increases
Solution Approach 1:
The OES sampling system provides real-time in-situ feedback during the etch process by continuously monitoring optical emission signals from multiple locations. This feedback enables immediate assessment of etch uniformity, allowing rapid optimization of etch recipes without requiring separate measurement steps, thereby improving productivity
Solution Approach 2:
The system maintains continuous OES signal sampling throughout the entire etch process duration, ensuring that useful measurement data is collected without interruption. This continuous monitoring eliminates idle measurement time and enables real-time process optimization, directly enhancing etch recipe development productivity
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
Provides in-situ feedback on etch uniformity, enabling faster development and optimization of etch recipes, and improving etch uniformity monitoring and control.
Implementation Method 1
The plurality of collimators corresponds to a plurality of collection cylinders for sampling optical emission spectroscopy (OES) signals with respect to a plurality of locations of a wafer in an etch chamber
Data Source
AI summary
An apparatus includes a base component and a plurality of collimators housed within the base component. Each collimator of the plurality of collimators corresponds to a respective location of a plurality of locations of a wafer in an etch chamber. The plurality of locations includes a center location of the wafer, a plurality of inner ring locations along an inner ring of the wafer associated with a first set of radially symmetric optical emission spectroscopy (OES) signal sampling paths, and a plurality of outer ring locations along an outer ring of the wafer associated with a second set of radially symmetric OES signal sampling paths.