Semiconductor Structure Right Angle Precision via Segmented Mask Etching
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Solution Overview
Problem
As integrated circuits miniaturize, the size of mask opening patterns decreases, leading to distortion during etching, which degrades the performance of semiconductor structures by causing contraction of right angles into fillets, increasing manufacturing costs and reducing precision.
Innovation Solution
A semiconductor structure manufacturing method involving a base substrate and array region with parallel strip structures, where a first mask structure is formed with a side plane perpendicular to the to-be-etched region, and a second mask layer with an opening pattern exposing the region to form discrete active regions with mapping right angles, reducing the need for multiple etching processes and mask layers, thus minimizing distortion and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single mask with opening pattern is used for etching structures in a same region, then manufacturing cost is reduced, but the pattern undergoes distortion during etching leading to degradation of semiconductor structure performance
Solution Approach 1:
The patent divides the mask structure into two separate masks: a first mask for etching the array region and a second mask for etching the base substrate. This segmentation allows each mask to be optimized for its specific function, preventing the distortion that occurs when a single mask is used for both regions. The first mask creates the initial pattern in the array region, while the second mask with its specific opening pattern and positioning creates the right-angled first active region in the base substrate without undergoing distortion.
Solution Approach 2:
The first mask structure formed in the array region acts as an intermediary element that serves dual purposes: it defines the array region structures and simultaneously serves as a reference for positioning the second mask. This intermediary structure enables precise alignment of the second mask's opening pattern to form the right-angled first active region, ensuring manufacturing precision while maintaining cost efficiency through a two-step process rather than multiple independent processes.
2Productivity
If mask opening pattern size is reduced for miniaturized integrated circuits, then circuit density is improved, but distortion during etching increases causing contraction of right angles into fillets
Solution Approach 1:
The patent addresses the angle precision problem by transitioning from a two-dimensional mask pattern to a three-dimensional structure formation process. The second mask's opening pattern is positioned and oriented to create vertical sidewalls in the base substrate, forming right-angled first active regions. This dimensional approach allows the formation of precise right angles through the etching depth rather than relying solely on the mask pattern's geometric accuracy, thereby maintaining angle precision even as circuit density increases through miniaturization.
3Manufacturing precision
If multiple independent process steps are used for different regions, then manufacturing precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the formation of two different structures into a coordinated two-step process: the first mask etches both the array region and forms the first mask structure, while the second mask uses this structure as a reference to etch the first active region. This merging approach achieves the precision of multiple independent processes while reducing manufacturing cost by using a sequential, coordinated process flow rather than completely separate fabrication steps for each region.
Data Source
AI summary
Embodiments of the present application provide a semiconductor structure and a manufacturing method thereof. The semiconductor structure manufacturing method includes: providing a base substrate and an array region, the array region being composed of strip structures arranged in parallel, the base substrate being made of a same material as the array region, and a thickness of the base substrate being greater than a thickness of the array region; etching the strip structure to form discrete first strip structures; base substrate providing a second mask layer, an opening pattern of the second mask layer exposing the to-be-etched region and the side plane, and a right angle being formed between an orthographic projection of the side plane and the opening pattern; form a first active region, the first active region having a mapping right angle corresponding to the right angle.