Semiconductor Trench Segmentation for Void-Free Insulating Film Fill
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Solution Overview
Problem
As the aspect ratio of trenches in semiconductor devices increases, the filling property of films decreases, leading to the formation of voids extending in the longitudinal direction, which can cause electrical shorts and reduce processing accuracy.
Innovation Solution
A semiconductor device manufacturing method that involves forming a mask film to divide trenches in the longitudinal direction, filling the resulting second trenches with an insulating film, and then removing the mask film to ensure complete coverage of the original trench with a second insulating film, using techniques like CVD or ALD to prevent void formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the aspect ratio of trenches is increased to achieve higher integration density, then the filling property of films decreases, leading to void formation
Solution Approach 1:
The patent divides a single deep trench into multiple shallower trenches by forming partition structures (mandrels) within the trench. This segmentation reduces the effective depth of each trench, improving film filling properties and preventing void formation while maintaining the overall high aspect ratio structure needed for integration density
Solution Approach 2:
The patent introduces mandrel structures as intermediary elements that serve dual purposes: they act as physical partitions to create shallower trenches for better film filling, and also serve as sacrificial structures that are later removed to create the final trench structure. This intermediary approach resolves the contradiction between maintaining deep trench structures and achieving good film filling
2Ease of manufacture
If conventional single-step trench filling is used, then the process is simple, but voids extending in the longitudinal direction form reducing reliability
Solution Approach 1:
The filling process is segmented into multiple steps: first filling shallower trenches created by mandrels, then removing mandrels, and finally filling the remaining spaces. This multi-step segmentation prevents longitudinal void formation and electrical shorts while maintaining reasonable process complexity
Solution Approach 2:
The patent performs preliminary actions by forming mandrel structures and creating shallower trenches before the final filling step. This preliminary structuring enables complete and void-free filling in subsequent steps, preventing reliability issues before they occur
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 effectively fills trenches without forming slit-shaped voids, enhancing the filling efficiency and reducing the risk of electrical shorts, thereby improving the accuracy and reliability of semiconductor device manufacturing.
Implementation Method 1
forming a mask film that covers part of a first trench, thereby dividing the first trench in the longitudinal direction to form one or more second trenches
Implementation Method 2
filling a first insulating film into the second trenches
Implementation Method 3
using techniques like CVD or ALD to prevent void formation
Implementation Method 4
forming a second insulating film that covers the entire first trench
Data Source
AI summary
A method for manufacturing a semiconductor device includes: forming a mask film such that it covers part of a first trench, thereby dividing the first trench in the longitudinal direction to form one or more second trenches; filling a first insulating film into the second trenches; removing the mask film; and forming a second insulating film such that it covers the entire first trench.