Lithography Process Window Control Under Actuator Constraints
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Solution Overview
Problem
Existing lithographic process control methods lack efficiency in monitoring and correcting process parameters to ensure accurate pattern application and high yield in semiconductor manufacturing.
Innovation Solution
A method to determine a process window within a process space defined by multiple parameters, using contour and failure mode data to optimize actuator configurations and control strategies for improved process compliance, combined with computational lithography techniques to simulate and predict pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional lithographic process control methods are used, then the manufacturing process can be maintained with existing equipment and procedures, but the efficiency in monitoring and correcting process parameters is insufficient, leading to reduced manufacturing precision and yield
Solution Approach 1:
The patent performs preliminary determination of the process window by simulating pattern formation under multiple process conditions before actual manufacturing. This advance preparation allows the system to identify acceptable parameter ranges and potential defects beforehand, enabling faster real-time control decisions without compromising manufacturing precision
Solution Approach 2:
The patent creates a virtual model (copy) of the manufacturing process through computational lithography simulations. This digital twin allows virtual testing of multiple process conditions and parameter combinations, enabling efficient process optimization without affecting actual production quality or requiring physical trial-and-error experiments
2Manufacturing precision
If multiple process parameters are monitored and simulated to determine process window, then the accuracy and compliance of pattern application is improved, but the computational complexity and time required for analysis increases
Solution Approach 1:
The patent segments the process window determination into distinct steps: obtaining contour data from multiple layers, determining failure modes, simulating pattern formation under various conditions, and analyzing results. This structured segmentation makes the complex computational task more manageable and enables parallel processing of different process conditions
Solution Approach 2:
The patent focuses computational resources on critical aspects by identifying and analyzing only the most significant failure modes and process conditions. Rather than exhaustively simulating all possible parameters, the method targets specific critical dimensions and failure scenarios that have the greatest impact on manufacturing precision
3Reliability
If process window determination is performed using comprehensive contour data and failure mode analysis, then the ability to identify and correct perturbations is enhanced, but the measurement and data processing requirements increase
Solution Approach 1:
The patent introduces computational lithography simulation as an intermediary between physical measurements and process control decisions. The simulation model translates measured contour data into predictions of pattern formation outcomes, enabling comprehensive process window determination without requiring direct measurement of all process parameters
Solution Approach 2:
The patent establishes a feedback loop where measured contour data from actual substrates is compared against simulated results under various process conditions. This feedback mechanism enables continuous refinement of process window determination and allows the system to adapt to actual manufacturing variations, enhancing reliability through iterative improvement
Data Source
AI summary
Disclosed is a method of determining a process window within a process space comprising obtaining contour data relating to features to be provided to a substrate across a plurality of layers, for each of a plurality of process conditions associated with providing the features across said plurality of layers and failure mode data describing constraints on the contour data across the plurality of layers. The failure mode data is applied to the contour data to determine a failure count for each process condition; and the process window is determined by associating each process condition to its corresponding failure count. Also disclosed is a method of determining an actuation constrained subspace of the process window based on actuation constraints imposed by the plurality of actuators.