Laser Spectroscopy Analysis Device for Semiconductor Etching Endpoint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plasma emission monitors and non-dispersive infrared analysis devices used in semiconductor processing lack reproducibility and sensitivity, especially with advancements in semiconductor miniaturization, making precise endpoint determination challenging.
Innovation Solution
An analysis device employing laser spectroscopy with a measurement unit that includes a laser light source, photodetector, and signal processing unit to measure reaction product concentrations or partial pressures, and an operation unit that calculates processed amounts through time integration and relationship data, allowing for precise monitoring of etching depth and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional plasma emission monitors (OES) are used to monitor etching endpoint, then endpoint detection is possible, but measurement precision and reproducibility deteriorate due to chamber variations, contamination, and individual unit differences
Solution Approach 1:
The patent replaces conventional plasma emission monitoring (optical detection) with laser spectroscopy-based measurement of reaction product concentrations. This substitution eliminates the problems of chamber variations, window contamination, and individual unit differences that plague OES systems, achieving both high measurement precision and excellent data reproducibility across different chambers and time points.
Solution Approach 2:
The patent changes the measured parameter from optical emission intensity (prone to interference) to reaction product concentration via laser spectroscopy. By measuring the concentration of specific reaction products that directly correlate with etching depth, the system achieves precise and reproducible endpoint detection independent of chamber conditions or contamination.
2Adaptability or versatility
If non-dispersive infrared (NDIR) analysis devices are used to measure reaction products, then measurement is possible without plasma, but measurement precision deteriorates due to insufficient resolution and sensitivity
Solution Approach 1:
The patent replaces NDIR analysis with laser spectroscopy measurement. The laser-based method provides superior resolution and sensitivity compared to NDIR, enabling precise endpoint measurement in both plasma and non-plasma processes while maintaining the versatility to work without plasma when needed.
3Productivity
If conventional measurement methods are used in advanced semiconductor miniaturization, then processing capability is maintained, but measurement precision deteriorates due to insufficient sensitivity for smaller feature sizes
Solution Approach 1:
The patent changes the measurement approach to monitor reaction product concentrations that directly correlate with material removal rate. This parameter change enables precise measurement of etching depth even for advanced node dimensions, maintaining processing capability while dramatically improving measurement accuracy for miniaturized features.
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
Enables precise measurement of reaction product concentrations and etching depth, improving reproducibility and sensitivity, and reducing errors due to contamination and chamber variations, thereby enhancing endpoint determination in semiconductor processing.
Implementation Method 1
a measurement unit that measures a concentration, a partial pressure, or a value related to the concentration or the partial pressure of a reaction product generated while a workpiece is being processed in workpiece processing; the measurement unit includes: a laser light source that irradiates target gas containing the reaction product with a laser beam
Implementation Method 2
a photodetector that detects a laser beam having passed through the target gas; and a signal processing unit that calculates the concentration, the partial pressure, or the value related to the concentration or the partial pressure of the reaction product based on a detection signal of the photodetector
Data Source
AI summary
The present invention is aimed to perform precise monitoring of the processed amount by which a workpiece is processed, and includes a measurement unit that measures a concentration or a partial pressure of a reaction product generated while the workpiece is being processed, and an operation unit that calculates the processed amount of the workpiece using an output value of the measurement unit. The measurement unit includes: a laser light source that irradiates target gas containing the reaction product with a laser beam; a photodetector that detects a laser beam having passed through the target gas; and a signal processing unit that calculates the concentration or the partial pressure of the reaction product based on a detection signal of the photodetector. The operation unit includes a time integration unit; a relationship data storage unit; and a processed amount calculation unit.