Electron Beam Proximity Correction for Sloped Substrate Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The proximity effect in electron beam lithography, caused by backscattering in substrates with varying surface profiles, is difficult to correct accurately using traditional methods, leading to inaccuracies in pattern dimensions on substrates with level differences or slopes.
Innovation Solution
A method that acquires drawing and surface profile data to calculate the energy distribution of backscattered electrons, adjusting the electron beam irradiation to correct the proximity effect by dividing the substrate into meshes and calculating specific energy distributions for flat, slope, and boundary portions, ensuring accurate pattern formation regardless of surface profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional proximity effect correction methods are used, then the correction process is simple, but the pattern dimension accuracy deteriorates on substrates with level differences or slopes
Solution Approach 1:
The substrate surface is divided into multiple mesh regions, with each mesh representing a local area with relatively uniform surface profile. This segmentation allows the correction method to handle complex surface variations by treating each small region independently with appropriate correction parameters, thereby improving pattern dimension accuracy without requiring an overly complex global correction model.
Solution Approach 2:
Different correction parameters are assigned to different mesh regions based on their local surface characteristics (flat, slope, or boundary portions). The electron beam irradiation conditions are locally optimized for each mesh type, applying specific correction factors that match the local surface profile. This local quality approach enables accurate correction on substrates with varying surface profiles while keeping the overall method manageable.
2Manufacturing precision
If uniform electron beam irradiation is applied, then the irradiation process is simple, but the pattern dimensions become inaccurate on substrates with varying surface profiles
Solution Approach 1:
The electron beam irradiation parameters are dynamically adjusted based on the surface profile of each mesh region. Instead of using fixed uniform irradiation, the system varies the irradiation conditions (such as beam energy or exposure time) according to the local surface characteristics, enabling accurate pattern formation on non-uniform substrates while maintaining operational simplicity through automated control.
Solution Approach 2:
The irradiation parameters (energy, intensity, or duration) are changed according to the mesh type (flat, slope, or boundary). By modifying these parameters based on pre-acquired surface profile data, the system achieves accurate pattern dimensions on substrates with level differences or slopes without requiring manual intervention or complex operational procedures.
3Manufacturing precision
If surface profile information is not considered, then the data processing is simple, but the proximity effect correction is inaccurate
Solution Approach 1:
Surface profile data is acquired and processed in advance, before the electron beam irradiation process. The substrate surface is scanned to create a height map, which is then divided into meshes and classified into different types (flat, slope, boundary). This preliminary action allows the correction parameters to be pre-calculated and stored, improving correction accuracy while keeping the actual irradiation process simple and fast.
Solution Approach 2:
The complex surface profile information is copied into a simplified mesh representation with discrete height values and classification labels. Instead of processing continuous surface data during irradiation, the system uses a pre-created digital model of the surface divided into discrete mesh regions, each with predetermined correction characteristics. This copying approach maintains high correction accuracy while significantly reducing processing complexity during operation.
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
This approach allows for precise correction of the proximity effect, ensuring accurate pattern dimensions on substrates with complex surface profiles, improving the accuracy of master plates and templates used in semiconductor processes.
Implementation Method 1
backscattering of an electron beam in a substrate
Data Source
AI summary
According to one embodiment, a proximity effect correcting method includes acquiring drawing information for drawing a pattern on a substrate with irradiation of an electron beam. The method further includes acquiring surface profile information related to a surface profile of the substrate. The method further includes calculating an energy distribution of a backscattered beam to be produced by backscattering of the electron beam in the substrate on a basis of the acquired drawing information and surface profile information. The method further includes calculating a required energy amount of the electron beam on a basis of the calculated energy distribution.