Auxiliary Pattern Layout Correction for Semiconductor Lithography EPE Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Optical Proximity Correction (OPC) methods for semiconductor manufacturing often result in edge placement errors (EPE) exceeding predetermined ranges due to mask rule restrictions, complicating the photolithography process and requiring extensive scripting and optimization efforts.
Innovation Solution
A method that involves adding an auxiliary pattern smaller than the photolithography resolution to the original layout pattern, followed by OPC to create a modified layout pattern, which includes a modified hole pattern and auxiliary pattern. This auxiliary pattern is used to compensate for light intensity loss and ensure the EPE is within a predetermined range, thereby satisfying mask rules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional OPC methods are applied to hole patterns, then the mask rule restrictions are satisfied, but the edge placement error (EPE) exceeds the predetermined range
Solution Approach 1:
The patent segments the hole pattern into multiple parts by introducing auxiliary patterns (sub-resolution assist features) around the main hole. This segmentation allows the OPC process to independently optimize each segment, enabling better EPE control while maintaining mask rule compliance. The auxiliary patterns are strategically placed to provide light intensity compensation without violating minimum feature size rules.
Solution Approach 2:
The patent introduces auxiliary patterns as intermediary elements between the main hole pattern and the illumination source. These intermediary features mediate the optical proximity effects by providing additional light paths that compensate for intensity loss in the main hole, thereby reducing EPE without directly modifying the critical hole dimensions in a way that would violate mask rules.
2Manufacturing precision
If OPC is applied to reduce optical proximity effect, then the resolution is improved, but the process complexity and scripting requirements increase significantly
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-placing auxiliary patterns around holes before the main OPC process. These auxiliary patterns are designed with fixed rules based on hole density and size criteria, eliminating the need for complex iterative optimization during the OPC process. This preliminary configuration simplifies subsequent OPC scripting and reduces process complexity.
Solution Approach 2:
The patent changes parameters by introducing auxiliary patterns with specific dimensional parameters (smaller than main holes but above mask rule minimums) and strategic positional parameters. These parameter changes provide systematic control over light intensity distribution, reducing the need for complex OPC algorithms and extensive scripting to achieve EPE control.
3Manufacturing precision
If auxiliary patterns smaller than exposure resolution are added, then the light intensity loss is compensated and EPE is reduced, but the pattern complexity increases
Solution Approach 1:
The patent applies local quality by placing auxiliary patterns selectively around specific holes based on local conditions such as hole size, hole density, and proximity to other features. Not all holes receive auxiliary patterns - only those that meet specific criteria. This localized approach provides EPE control where needed while minimizing overall pattern complexity and avoiding unnecessary features in regions where they are not required.
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
The method effectively reduces EPE within a predetermined range, satisfies mask rules, provides sufficient depth of focus, and simplifies the OPC process by reducing the need for extensive scripting and optimization, improving the efficiency of photolithography.
Implementation Method 1
The auxiliary pattern can have a dimension smaller than an exposure resolution in a photolithography process... when the first modified layout pattern is simulated to obtain an actual layout pattern, the actual layout pattern has an edge placement error (EPE) within a predetermined range
Data Source
AI summary
A method for correcting layout pattern and a mask having the corrected layout pattern thereon are provided. In an exemplary method, a first layout pattern including a plurality of first hole patterns can be provided to form an auxiliary pattern in each first hole pattern and to obtain a second layout pattern. The auxiliary pattern can have a dimension smaller than an exposure resolution in a photolithography process. The second layout pattern can then be processed by an optical proximity correction (OPC) to obtain a first modified layout pattern. The first modified layout pattern can include a plurality of modified first hole patterns modified by the OPC. The first modified layout pattern can be simulated to obtain an actual layout pattern such that the actual layout pattern and the first layout pattern have an edge placement error (EPE) within a predetermined range.