Gate Isolation Layer Structure for FinFET Contact Short Prevention
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Solution Overview
Problem
In semiconductor devices, the existing technologies face challenges in effectively isolating gate structures from source/drain contact plugs, leading to potential electrical short circuits and reduced reliability, especially in miniaturized FinFET or multi-bridge channel transistor designs.
Innovation Solution
Incorporating a gate isolation layer on the gate spacer with dry etching resistance, which remains intact during the formation of contact plugs, ensuring electrical insulation between the gate electrode and the contact plugs and preventing short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gate isolation layer is not provided, then the device complexity is reduced, but electrical insulation between gate electrode and contact plugs cannot be ensured leading to short circuits
Solution Approach 1:
A gate isolation layer is introduced as an intermediary insulating structure between the gate electrode and source/drain contact plugs. This layer acts as a mediator that prevents direct electrical contact between conductive elements, thereby ensuring electrical insulation and preventing short circuits while maintaining device functionality.
Solution Approach 2:
The gate isolation layer is segmented to be disposed at specific locations where electrical insulation is critical - between the gate electrode and contact plugs. This targeted segmentation approach provides necessary insulation only where required, avoiding unnecessary complexity in other device regions.
2Manufacturing precision
If the gate isolation layer is not dry etching resistant, then manufacturing precision is reduced due to layer removal, but process complexity is lowered
Solution Approach 1:
The gate isolation layer is designed with specific material properties that confer dry etching resistance. By changing the physical and chemical parameters of the isolation layer material, it maintains structural integrity during dry etching processes used to form contact plugs, ensuring precise isolation without being removed or damaged.
Solution Approach 2:
The gate isolation layer is formed with dry etching resistant properties before the contact plug formation process. This preliminary preparation ensures that when dry etching is subsequently performed to create contact plugs, the isolation layer remains intact and continues to provide electrical insulation, maintaining manufacturing precision.
3Productivity
If device miniaturization is pursued, then productivity is improved, but reliability deteriorates due to increased short circuit risk
Solution Approach 1:
The gate isolation layer extends in the vertical dimension above the gate spacer, creating a three-dimensional isolation structure. This vertical extension ensures that even as devices are miniaturized in planar dimensions, the isolation layer maintains sufficient electrical insulation distance, preventing short circuits between closely spaced contact plugs and gate electrodes.
Solution Approach 2:
In miniaturized devices where spacing between components is reduced, the gate isolation layer serves as a critical intermediary insulating barrier. It maintains electrical isolation between the gate electrode and contact plugs despite the reduced lateral dimensions, enabling high integration density without compromising reliability.
Data Source
AI summary
A semiconductor device includes active regions on a substrate, a gate structure intersecting the active regions, a source/drain region on the active regions and at a side surface of the gate structure, a gate spacer between the gate structure and the source/drain region, the gate spacer contacting the side surface of the gate structure, a lower source/drain contact plug connected to the source/drain region, a gate isolation layer on the gate spacer, an upper end of the gate isolation layer being at a higher level than an upper surface of the gate structure and an upper surface of the lower source/drain contact plug, a capping layer covering the gate structure, the lower source/drain contact plug, and the gate isolation layer, and an upper source/drain contact plug connected to the lower source/drain contact plug and extending through the capping layer.