Semiconductor Patterning via Displaced Dual Mask Layers
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Solution Overview
Problem
The existing methods for manufacturing semiconductor devices are limited by the resolution of the imaging system, which restricts the dimensions of microcircuits and structures such as trenches, making it difficult to create smaller features.
Innovation Solution
The method involves creating a second pattern on the mask layers that is displaced relative to the first pattern, allowing for the removal of mask layers and underlying material with higher precision, enabling the creation of smaller structures by utilizing the remaining mask layers as a mask for selective etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional imaging systems are used to create patterns, then the manufacturing process is simple, but the minimum feature size is limited by the imaging system resolution
Solution Approach 1:
The patent divides the single mask layer into two separate mask layers (first mask layer and second mask layer). The first mask layer is used for initial pattern formation, and the second mask layer is used for creating the displaced pattern. This segmentation allows each mask layer to serve a specific function, enabling feature sizes below the imaging system resolution limit while keeping the process manageable through clear division of tasks.
Solution Approach 2:
The patent introduces a spatial displacement between the first pattern and the second pattern. By creating the second pattern at a displaced location relative to the first pattern, the method effectively uses the displacement distance as a new dimension of control. This allows the final feature size to be determined by the displacement accuracy rather than the imaging system resolution, transcending the traditional two-dimensional pattern formation limits.
2Manufacturing precision
If the imaging system resolution is improved to create smaller features, then the minimum feature size decreases, but the equipment complexity and cost increase
Solution Approach 1:
The patent introduces a second mask layer as an intermediary between the imaging system and the final pattern. Instead of directly using the imaging system to create the final small features, the first mask layer serves as an intermediary that is later removed, allowing the second mask layer to define the final pattern. This intermediary approach enables the use of existing imaging systems to achieve higher effective resolution than the imaging system alone could provide.
Solution Approach 2:
The patent changes the critical parameter from imaging system resolution to mask displacement accuracy. By making the pattern formation dependent on the displacement distance between the first and second patterns rather than the imaging system resolution, the method transforms the limiting factor. This parameter change allows using standard imaging systems while achieving higher effective resolution through precise displacement control.
3Manufacturing precision
If a single mask layer is used for pattern formation, then the process is simpler, but the achievable feature size is larger
Solution Approach 1:
The patent performs preliminary pattern formation using the first mask layer before the final pattern creation. The first pattern is created as a preliminary step, then the first mask layer is removed, and the second mask layer is used to create the displaced second pattern. This preliminary action allows the final small features to be defined by the displacement rather than the initial pattern dimensions, achieving smaller feature sizes through the two-stage process.
Solution Approach 2:
The patent inverts the traditional approach by having the second mask layer (created from a displaced pattern) define the final pattern rather than the first mask layer. Instead of using the directly imaged pattern as the final pattern, the method uses the displaced second pattern as the definitive pattern, with the first pattern serving as a temporary intermediate structure that is removed. This inversion allows the final features to be smaller than the imaging system resolution.
Data Source
AI summary
A method of manufacturing a semiconductor device with precision patterning is disclosed. A structure of a small dimension is created in a material, such as a semiconductor material, using a first and a second pattern, the patterns being identical but displaced over a distance with respect to each other. Two mask layers are used, wherein the first pattern is etched into the upper mask layer with a selective etch, and the second pattern is created on the upper mask layer or on the lower mask layer at locations where the upper mask layer has been removed. A part of the lower mask layer and/or the upper mask layer is etched according to the second pattern, resulting in a mask formed by remaining parts of the lower and upper mask layers, the mask having a structure with a dimension determined by a displacement of the second pattern with respect to the first pattern.