Raman Spectroscopy for Polyimide Dissolution Rate Monitoring
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Solution Overview
Problem
Conventional methods for evaluating the polyimide dissolution rate are time-consuming, require skilled personnel, and are prone to fluctuations, making them unsuitable for automated or on-line/in-line inspections, which complicates the production of uniform polyimide quality in semiconductor manufacturing.
Innovation Solution
The method involves using Raman spectroscopy to measure the Raman spectral intensity of imide groups or carboxyl groups in polyimides, comparing it to known standards to evaluate the dissolution rate, and employing this data for reaction control during polyimide production, enabling on-line or in-line monitoring and adjustment of processing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional dissolution rate measurement methods are used (actual dissolution testing), then measurement accuracy is achieved, but measurement time is excessive and automation is impossible
Solution Approach 1:
The patent replaces the mechanical/chemical dissolution testing system with a spectroscopic measurement system. Raman spectroscopy measures the intensity of imide group peaks to evaluate dissolution rate, substituting the time-consuming actual dissolution process with a rapid optical measurement that provides comparable accuracy without requiring lengthy etching and thickness measurement procedures
Solution Approach 2:
The patent creates a spectral copy or proxy measurement of the dissolution rate property. Instead of measuring the actual dissolution process, it measures the Raman spectral intensity of imide groups which correlates with dissolution rate, providing a surrogate measurement that is both rapid and accurate
2Measurement precision
If conventional dissolution rate measurement methods are used, then dissolution rate evaluation is obtained, but operator skill dependency and measurement fluctuation increase
Solution Approach 1:
The patent replaces manual dissolution testing operations with automated Raman spectroscopy measurement. The spectroscopic method eliminates dependence on operator skill for conducting dissolution tests, measuring film thickness, and calculating rates, as the instrument automatically acquires spectral data and the dissolution rate is evaluated from peak intensity ratios
Solution Approach 2:
The measurement system performs self-evaluation by automatically acquiring Raman spectra and calculating dissolution rate from the imide group peak intensity. The system does not require skilled operators to conduct complex dissolution procedures or interpret results, as the spectral measurement and evaluation are automated
3Ease of operation
If Raman spectroscopy is used for dissolution rate evaluation, then measurement simplicity and automation capability are achieved, but measurement precision must be maintained
Solution Approach 1:
The patent changes the measurement parameter from physical dissolution (thickness reduction over time) to spectral parameter (Raman peak intensity). By measuring the intensity of imide group peaks at specific wavenumbers and calculating intensity ratios, the method maintains measurement precision while achieving simplicity and automation capability
4Productivity
If conventional production methods are used, then polyimide production is achieved, but quality uniformity and stability are difficult to obtain
Solution Approach 1:
The patent implements feedback control by measuring dissolution rate via Raman spectroscopy during production and using this information to control reaction conditions. The real-time spectral measurement provides feedback on polymerization progress and product quality, enabling adjustments to maintain uniformity and stability
Solution Approach 2:
The patent performs preliminary evaluation of dissolution rate during the production process itself rather than after completion. By measuring Raman spectra during polymerization, the system can assess quality early and make adjustments before the production cycle completes, ensuring uniformity
Data Source
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AI summary
A method of evaluating the dissolution rate of a polyimide by Raman spectroscopy, wherein the Raman spectral intensity I(a) of imide groups contained within the polyimide is measured, and I(a) is then compared with the Raman spectral intensity I(b) of imide groups contained within a polyimide with a known dissolution rate. The polyimides are preferably obtained using an aromatic tetracarboxylic dianhydride and/or an aromatic diamine.