Semiconductor Spacer Walls Alleviate Trench Rounding
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Solution Overview
Problem
As technology nodes shrink, the formation of interconnecting structures in semiconductor manufacturing becomes increasingly difficult due to the challenges of achieving precise dimensions and reducing rounding errors, which affects the electrical performance and reliability of semiconductor devices.
Innovation Solution
A method involving the formation of a core layer, a hard mask layer, and spacers to create isolated mask trenches and target trenches, using a combination of deposition and etching processes to improve the perpendicularity of the spacer walls and reduce rounding errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional interconnecting structure formation processes are used, then manufacturing simplicity is maintained, but manufacturing precision deteriorates due to rounding errors and difficulty in achieving precise dimensions
Solution Approach 1:
The formation process is divided into multiple sequential steps: forming first mask trenches with spacers, removing core layer, forming second mask trenches with spacers, and finally forming target trenches. This segmentation allows each step to be optimized independently, achieving precise dimensional control while managing process complexity through systematic breakdown
Solution Approach 2:
Mask trenches and spacers are formed in advance before the actual target trench formation. The spacers are deposited and etched to create precise boundary definitions before removing the core layer and forming the final interconnecting structures, ensuring dimensional accuracy is established early in the process
2Area of stationary object
If technology node size is reduced to increase integration level, then area utilization is improved, but manufacturing precision deteriorates due to increased difficulty in forming small interconnecting structures
Solution Approach 1:
The process transitions from planar patterning to three-dimensional spacer formation and mask trench creation. By utilizing vertical spacer deposition on mask trench sidewalls, the method achieves precise lateral dimensional control through vertical film thickness control, enabling accurate small-scale interconnecting structure formation while maximizing wafer area utilization
3Manufacturing precision
If spacer wall perpendicularity is improved through deposition and etching processes, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
The spacer formation process uses self-aligned deposition and etching where the spacer material automatically conforms to the mask trench sidewalls. The process leverages the inherent properties of conformal deposition and anisotropic etching to achieve perpendicular walls without requiring additional alignment steps or complex process control, allowing precision improvement while managing complexity through self-organizing process behavior
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 enhances the appearance quality and dimensional accuracy of the target trenches, thereby improving the performance and reliability of semiconductor devices by alleviating rounding issues and maintaining high perpendicularity of the spacer walls.
Implementation Method 1
forming a first spacer on a side wall of the mask sub-trench
Implementation Method 2
forming a first spacer on a side wall of the mask sub-trench
Implementation Method 3
forming a first mask trench in the core layer exposed from the first mask opening
Implementation Method 4
forming a first mask trench in the core layer exposed from the first mask opening
Data Source
AI summary
A semiconductor structure and a method for forming same are provided. In one form, a forming method includes: providing a base, where a core layer is formed on the base, a hard mask layer is formed on the core layer, and a first mask opening is formed in the hard mask layer; forming a first mask trench in the core layer exposed from the first mask opening, the first mask trench including a plurality of mask sub-trenches along an extending direction, where the mask sub-trenches are isolated from each other using the core layer exposed from the first mask opening; forming a first spacer on a side wall of the mask sub-trench; removing a core layer of a region in which the first mask opening is located, and forming, at a position corresponding to the core layer, a second mask trench enclosed by the first spacer and the base, the second mask trench and the first mask trench being isolated from each other using the first spacer; and forming a second spacer on a side wall of the second mask trench, where both the first spacer and the base, and the second spacer and the base, enclose a first target trench. The first spacer and the second spacer whose side walls contact with each other are used as a cutting member, alleviating rounding of a head of the first target trench.