Dummy Region Segmentation for Void Migration Prevention
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Solution Overview
Problem
Conventional semiconductor device manufacturing methods face issues with dummy regions leaning or collapsing during planarization, leading to electrical insulation asymmetry and void migration in gate electrodes, which can cause device failure.
Innovation Solution
The method involves forming an isolation layer pattern between dummy and active regions, creating grooves using anisotropic and isotropic etching processes, and forming gate electrodes with voids that are symmetrically distributed to prevent void migration and ensure proper electrical insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If dummy regions are formed to prevent active regions from leaning during planarization, then structural stability is improved, but the dummy regions themselves may lean or collapse when their size is relatively small
Solution Approach 1:
The dummy region is divided into multiple sub-regions separated by isolation layer patterns, creating a segmented structure that prevents leaning while maintaining overall stability
Solution Approach 2:
Isolation layer patterns are introduced as intermediary structures between dummy regions and active regions, providing mechanical support and preventing leaning during planarization
2Reliability
If isolation layer pattern is formed between dummy regions, then electrical insulation is achieved, but asymmetry in groove sections occurs due to minimal etching of isolation layer
Solution Approach 1:
The isolation layer pattern is selectively positioned and dimensioned to provide local electrical insulation while minimizing interference with groove symmetry
Solution Approach 2:
The etching process is controlled to partially remove the isolation layer pattern only where necessary, maintaining electrical insulation while reducing asymmetry in groove sections
3Ease of manufacture
If gate electrode layer is formed to fill grooves, then gate electrodes are created, but voids are generated that can migrate and cause device failure
Solution Approach 1:
Grooves are pre-formed with specific geometries and isolation structures are preliminarily positioned to prevent void formation during subsequent gate electrode layer deposition
Solution Approach 2:
The geometry parameters of grooves and the deposition parameters of gate electrode layer are optimized to eliminate void formation while maintaining manufacturability
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 prevents dummy region leaning, maintains electrical insulation symmetry, and reduces the risk of device failure by ensuring symmetric void distribution in the gate electrodes.
Implementation Method 1
an anisotropic etching process is performed on the silicon oxide layer 50 so that portions of the silicon oxide layer 50 may be selectively removed
Implementation Method 2
portions of the dummy regions 11 and portions of the active regions 12 that are exposed through the first grooves 1c and the second grooves, respectively, are isotropically etched
Data Source
AI summary
A semiconductor device capable of suppressing void migration is provided. The semiconductor device includes a dummy region extending in a first direction substantially perpendicular to a second direction in which a word line extends. In addition, an isolation layer pattern may not cut the dummy region in the second direction. Consequently, leaning of the dummy region and void migration are prevented. A method of fabricating the semiconductor device is also provided.