Multi-Gate Semiconductor Isolation Structure for Short-Channel Control
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Solution Overview
Problem
Current semiconductor devices face challenges in improving performance and reliability, particularly in scaling techniques for increasing density and controlling current while suppressing short channel effects.
Innovation Solution
A semiconductor device design featuring a multi-gate transistor with a gate isolation structure comprising a lower isolation pattern and an upper isolation pattern, where the lower isolation pattern's width increases and then decreases in the downward direction, and the upper isolation pattern protrudes above the gate electrodes, enhancing gate isolation and control capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multi-gate transistor with three-dimensional channel is used, then current control capability and short channel effect suppression are improved, but device complexity increases
Solution Approach 1:
The gate electrode is divided into multiple gates (first gate electrode and second gate electrode) that wrap around the channel region, creating a multi-gate structure. This segmentation allows better control of the three-dimensional channel while managing the complexity through systematic arrangement of multiple gate components.
Solution Approach 2:
The transistor transitions from a planar two-dimensional channel to a three-dimensional channel structure with gates extending in multiple directions. The gate electrodes are positioned to control the channel from multiple spatial dimensions, improving control capability while the gate isolation structure manages the resulting complexity.
2Productivity
If gate length is not increased, then device density is improved, but short channel effect control becomes more difficult
Solution Approach 1:
The channel region is formed as a three-dimensional structure (fin or nanowire) that extends vertically from the substrate. This dimensional change allows the gate to control the channel effectively even when the horizontal gate length is reduced, thereby maintaining short channel effect suppression while increasing device density.
Solution Approach 2:
The channel is segmented into multiple active patterns (first active pattern and second active pattern) with field insulating layers between them. This segmentation creates multiple independent three-dimensional channels, each controlled by gate electrodes, allowing higher density while maintaining effective gate control over each channel region.
3Reliability
If a gate isolation structure with multi-layer isolation pattern is used, then gate electrode isolation is improved, but manufacturing complexity increases
Solution Approach 1:
The gate isolation structure is segmented into a lower isolation pattern and an upper isolation pattern formed at different stages. The lower isolation pattern is formed first to provide initial isolation, followed by the upper isolation pattern to complete the isolation. This segmentation improves isolation reliability while breaking down the complex fabrication into manageable sequential steps.
Solution Approach 2:
The lower isolation pattern is formed in advance before the gate electrodes are fully positioned. This preliminary isolation structure provides a foundation that simplifies subsequent manufacturing steps, as the basic isolation framework is already in place before adding the upper isolation pattern and completing the gate electrode formation.
4Productivity
If active patterns are spaced closer together, then device density is improved, but electrical interference between adjacent structures increases
Solution Approach 1:
Field insulating layers are introduced as intermediary structures between the first active pattern and the second active pattern. These insulating layers act as electrical barriers that prevent interference between adjacent active patterns, allowing them to be spaced closer together for higher density while maintaining electrical isolation.
Solution Approach 2:
The field insulating layers are extracted or removed from directly between the active patterns in certain regions to allow closer spacing where interference is not an issue, while maintaining insulation where needed. This selective removal optimizes density while managing electrical interference.
Data Source
AI summary
A semiconductor device includes: a first active pattern extended in a first direction on a substrate; a second active pattern extended in the first direction and spaced apart from the first active pattern in a second direction on the substrate; a field insulating layer between the first active pattern and the second active pattern on the substrate; a first gate electrode on the first active pattern; a second gate electrode on the second active pattern; and a gate isolation structure separating the first gate electrode and the second gate electrode from each other on the field insulating layer, wherein a width of the gate isolation structure in the second direction varies in a downward direction from the upper isolation pattern.