Short-Range Flare Model Parameter Optimization for Lithography Simulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithographic simulation tools fail to accurately account for short-range flare, leading to reduced image contrast and critical dimension uniformity, which is critical as device pattern dimensions decrease and optical proximity correction requirements become more stringent.
Innovation Solution
A method to extract and optimize short-range flare model parameters from measured data using Power Spectral Density functions, such as the ABC model, and genetic parameter extraction algorithms, ensuring that simulated flare data matches measured data within a predefined error tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If short-range flare effects are not compensated in simulation, then simulation speed and simplicity are maintained, but image contrast and critical dimension uniformity deteriorate
Solution Approach 1:
The patent changes the parameters of the simulation model by introducing flare model parameters (such as flare intensity and spatial distribution parameters) that quantify short-range flare effects. These parameters are optimized to match measured data, allowing the simulation to accurately represent flare without requiring complex physical models of the flare generation mechanisms.
Solution Approach 2:
The patent introduces an intermediary flare model that acts as a mediator between the basic optical simulation and the actual flare effects. This model uses measured data to characterize flare and applies it as a correction layer, simplifying the overall system while improving accuracy.
2Measurement precision
If flare model parameters are extracted and optimized from measured data, then simulation accuracy improves, but computational time and processing complexity increase
Solution Approach 1:
The patent performs preliminary action by extracting and optimizing flare model parameters in advance, before actual production simulations are run. The parameters are determined once from measured data and then reused in subsequent simulations, amortizing the initial computational cost over many uses.
Solution Approach 2:
The patent implements feedback by comparing simulated flare data with measured flare data and using this comparison to optimize the flare model parameters. This iterative feedback process continues until the simulated data matches measured data within acceptable tolerances, ensuring high accuracy.
3Illumination intensity
If short-range flare is measured and compensated, then image contrast improves, but measurement and processing requirements increase
Solution Approach 1:
The patent uses copying by creating a digital representation (model) of the flare effects based on measured data. Instead of directly measuring and correcting every aspect of flare in real-time, the system creates a simplified model that captures the essential flare characteristics and applies it computationally.
Data Source
AI summary
A process of obtaining short-range flare model parameters representing a short-range flare which degrades a contrast of an image generated by a lithography tool, is disclosed. Short-range flare is measured from the image to obtain measured short-range flare data. A simulation is performed based on short-range flare model parameters to obtain simulated short-range flare data. The simulated short-range flare data is compared with the measured short range flare data. It is determined whether the short-range flare model parameters used in the simulation is appropriate based on the comparison result. The short-range flare model parameters is optimized according to the measured short-range data and the simulated short-range flare data if the short-range flare model parameters used for the simulation is not appropriate.