Semiconductor Etching Structure for Complete Selective Patterning
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Solution Overview
Problem
In semiconductor manufacturing, selective etching is often incomplete due to the influence of adjacent regions, which prevents the formation of a preset opening pattern, leading to incomplete etching of the target layer.
Innovation Solution
A method involving a substrate with distinct regions, where a target layer, mask layers, and an intermediate layer are formed with specific trench structures and sacrificial layers, followed by a maskless dry etching process to ensure complete etching of the target layer, addressing the issue of incomplete etching by managing the height differences and material distribution across regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mask layer with opening pattern is formed before selective etching, then the target layer can be etched selectively, but adjacent regions may affect the etching process causing incomplete etching
Solution Approach 1:
The substrate is divided into multiple regions (first region, second region, third region) with different etching requirements. The intermediate layer is segmented into regions with different trench arrangements - the first region has trenches with sacrificial layers while the second region has different trench configurations. This segmentation allows each region to be etched independently with appropriate protection, preventing adjacent region interference and ensuring complete etching throughout.
Solution Approach 2:
Trenches are formed in the intermediate layer before the selective etching of the target layer. Sacrificial layers are deposited in these trenches in advance to provide protection during etching. The fill layer is formed to fill these trenches, creating a protective structure before the actual target layer etching begins. This preliminary preparation ensures that when etching occurs, the sacrificial layers are already in position to prevent etching agent penetration into adjacent regions.
2Manufacturing precision
If photoresist or mask layer is used to form opening pattern, then selective etching can be performed, but the process complexity increases
Solution Approach 1:
The patent extracts the masking function from traditional photoresist/mask layers and transfers it to the intermediate layer with trenches and sacrificial layers. Instead of using a separate mask layer that needs to be formed, patterned, and removed, the intermediate layer itself provides the masking function through its trench structure and sacrificial layer configuration. This eliminates the need for photoresist coating, exposure, and development steps, reducing process complexity while maintaining selective etching capability.
Solution Approach 2:
The intermediate layer serves multiple functions: it provides structural support, defines region boundaries, contains trenches that hold sacrificial layers, and acts as a mask during etching. The fill layer also serves dual purposes by filling trenches to provide protection while maintaining surface planarity. This multi-functionality reduces the number of separate process steps needed compared to traditional mask-based approaches.
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 method enables complete selective etching of the target layer, ensuring accurate formation of the target pattern without material collapse or uneven etching, thereby improving the precision and reliability of semiconductor structure manufacturing.
Implementation Method 1
perform a maskless dry etching process to remove a portion of the fill layer in the first region
Data Source
AI summary
The embodiment of the application provides a method of manufacturing a semiconductor structure, which comprises the following steps: forming a target layer, a first mask layer, an isolation layer and an intermediate layer sequentially on a substrate, wherein first trench is disposed in the intermediate layer in the first region and second trench is disposed in the intermediate layer in the second region; forming a fill layer, and the difference in the height between the top surface of the fill layer in the first region and in the second region is less than or equal to a first preset value; removing a portion of the fill layer in the first region until the top surface of the sacrificial layer is exposed; removing the sacrificial layer; and etching a portion of the target layer through the first opening, wherein the remaining target layer forms a target pattern.