Semiconductor Isolation Structure With Protruding Nitride Liner
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Solution Overview
Problem
Existing semiconductor devices face challenges in achieving reliable isolation structures for transistors, particularly in the removal of metal layers from recessed portions, which can lead to defects such as bridge failures due to residual metal residues.
Innovation Solution
The semiconductor device incorporates isolation structures with a nitride liner that protrudes from the inner wall oxide and filling insulation patterns, creating recessed portions with increased widths and flat bottoms, allowing for easy removal of metal layers and reducing residual defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional isolation structures are used without protruding liners, then the structure is simpler and manufacturing is easier, but metal layers cannot be completely removed from recessed portions leading to residual defects
Solution Approach 1:
The isolation structure is segmented into multiple functional layers: inner wall oxide pattern for isolation, nitride liner layer for defining recessed portions, and filling insulation pattern for completing the isolation. This segmentation allows each layer to perform its specific function, with the nitride liner creating protruding portions that define wider recessed portions for complete metal removal.
Solution Approach 2:
The nitride liner is formed to protrude from the inner wall oxide pattern in the vertical dimension, creating a three-dimensional structure with recessed portions that have increased width. This dimensional change allows etching processes to access and completely remove metal layers from the recessed portions, preventing residual defects.
2Ease of manufacture
If the nitride liner protrudes from the inner wall oxide pattern, then recessed portions with increased width are created for easy metal removal, but the manufacturing process becomes more complex
Solution Approach 1:
The nitride liner is formed preliminarily before metal layer deposition, creating the recessed portion structure in advance. This preliminary action ensures that when metal layers are later deposited and need to be removed, the recessed portions are already prepared with increased width for complete and easy metal removal, avoiding residual defects.
Solution Approach 2:
The nitride liner acts as an intermediary structure between the inner wall oxide pattern and the filling insulation pattern. It defines the recessed portions and facilitates the complete removal of metal layers, serving as a mediator that enables easy metal removal while maintaining structural integrity.
3Reliability
If conventional trench filling is used without protruding structures, then the isolation structure is simpler, but residual metal residues cause bridge failures
Solution Approach 1:
The isolation structure is segmented into distinct layers with the nitride liner forming protruding portions that define recessed portions. This segmentation creates specific geometric features that enable complete metal removal, preventing residual metal residues that would cause bridge failures.
Solution Approach 2:
The nitride liner protrudes in the vertical dimension to create recessed portions with increased horizontal width. This dimensional transformation ensures that etching processes can access and completely remove metal layers, eliminating the risk of residual metal residues causing bridge failures.
Data Source
AI summary
A semiconductor device includes first and second trenches in respective first and second regions in a substrate, a first isolation structure having a first inner wall oxide pattern, a first liner, and a first filling insulation pattern sequentially stacked I the first trench, a second isolation structure having a second inner wall oxide pattern, a second liner, and a second filling insulation pattern sequentially stacked I the second trench, a first gate structure having a first high-k dielectric pattern, a first P-type metal pattern, and a first N-type metal pattern sequentially stacked on the first region, and a second gate structure having a second high-k dielectric pattern and a second N-type metal pattern sequentially stacked on the second region, wherein the first and second liners protrude above upper surfaces of the first and second inner wall oxide patterns and the first and second filling insulation patterns, respectively.