Ring-Shaped Protection Spacer for Gate-to-Contact Isolation
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Solution Overview
Problem
The increasing integration density and complexity of semiconductor devices lead to challenges in preventing bridge issues between gate electrodes and source/drain contact plugs, which can result in reduced reliability and increased parasitic capacitance, affecting performance and yield.
Innovation Solution
Incorporating a protection spacer with a ring shape, made of low-k dielectric material, between the gate spacer and source/drain contact plug to prevent bridge formation and reduce parasitic capacitance, while also using auxiliary insulating patterns to reinforce damaged gate spacers and improve fabrication processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If integration density is increased, then device functionality and performance are improved, but the risk of bridge issues between gate electrodes and source/drain contact plugs increases
Solution Approach 1:
A protection spacer is introduced as an intermediary structure between the gate electrode and source/drain contact plug. This protection spacer prevents direct contact or bridging between these conductive elements while allowing the integration density to increase. The protection spacer acts as a physical barrier that maintains electrical isolation even as device dimensions are reduced and elements are placed closer together.
Solution Approach 2:
The gate structure is segmented into multiple components: gate electrode, gate spacer, and protection spacer. This segmentation allows each component to perform its specific function - the gate electrode provides electrical control, the gate spacer provides initial isolation, and the protection spacer provides additional protection against bridging. By dividing the isolation function into separate structural elements, the design can maintain reliability while increasing integration density.
2Productivity
If gate spacer width is reduced to increase integration density, then device size is reduced, but gate spacer damage during fabrication increases
Solution Approach 1:
The protection spacer is formed beforehand to cushion and protect the gate spacer during subsequent fabrication processes. By introducing this protective structure in advance, the gate spacer is shielded from damage that might occur during etching, deposition, or other manufacturing steps. This allows the gate spacer to be made narrower for higher integration density without compromising its structural integrity during fabrication.
Solution Approach 2:
The protection spacer is formed prior to critical fabrication steps that could damage the gate spacer. This preliminary action establishes a protective framework before the gate spacer is vulnerable to process-induced damage. The protection spacer serves as a sacrificial or reinforcing element that absorbs or prevents damage to the narrower gate spacer structure.
3Area of stationary object
If elements are placed closer together to increase integration density, then device area is reduced, but parasitic capacitance between gate electrode and source/drain contact plug increases
Solution Approach 1:
The protection spacer serves as an intermediary dielectric structure between the gate electrode and source/drain contact plug. By introducing this additional insulating layer, the electric field coupling between these conductive elements is reduced, thereby decreasing parasitic capacitance. The protection spacer increases the effective insulation distance even though the physical spacing between elements is reduced for higher integration density.
Data Source
AI summary
A semiconductor device includes a gate pattern crossing over a substrate, the gate pattern including a gate insulating layer, a gate electrode, and a gate capping pattern sequentially stacked on the substrate, a gate spacer covering a sidewall of the gate pattern, a source/drain pattern on the substrate, the source/drain pattern being adjacent to the sidewall of the gate pattern, a contact pad on the source/drain pattern, a top surface of the contact pad being lower than a top surface of the gate electrode, a source/drain contact plug on the contact pad, and a protection spacer between the gate spacer and the source/drain contact plug, the protection spacer having a ring shape enclosing the source/drain contact plug.