Contact Plug Protrusion Structure for Low-Resistance IC Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices, such as MOSFETs, are scaled down, their operating characteristics deteriorate due to reduced size, leading to challenges in achieving high integration and performance.
Innovation Solution
The implementation of a semiconductor device design featuring a contact plug with a protrusion that extends above the interlayer insulating layer, allowing the conductive line to partially overlap with the protrusion, thereby increasing the contact area and reducing resistance, along with a line barrier pattern and etch stop layer to enhance electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the contact plug is scaled down to match the reduced size of MOSFETs, then the device integration is improved, but the contact area between the conductive line and contact plug is reduced, leading to increased resistance and deteriorated operating characteristics
Solution Approach 1:
The contact plug is designed with a protrusion that extends vertically above the top surface of the first interlayer insulating layer. This vertical extension adds a dimensional element to the contact plug structure, increasing the contact area with the conductive line without expanding the horizontal footprint, thereby maintaining high device integration while improving operating characteristics through enhanced electrical contact.
2Quantity of substance
If the contact plug size is reduced for high integration, then the density of devices is improved, but the contact resistance increases due to reduced contact area
Solution Approach 1:
The protrusion structure extends the contact plug vertically, increasing the contact area with the conductive line without increasing the horizontal device footprint. This dimensional approach allows higher device density while maintaining low contact resistance through enhanced contact area.
Solution Approach 2:
The protrusion of the contact plug is positioned within the region where the conductive line is formed, creating a nested configuration where the conductive line overlaps with the protrusion. This nesting increases the contact area and reduces contact resistance while maintaining compact device structure for high integration.
3Reliability
If the contact area between conductive line and contact plug is increased to reduce resistance, then the electrical characteristics are improved, but the device complexity increases
Solution Approach 1:
The protrusion adds vertical dimension to the contact plug, increasing contact area with the conductive line. This approach improves electrical characteristics while maintaining relatively simple fabrication processes, as the protrusion can be formed through standard deposition and etching techniques without requiring complex multi-step structuring.
Data Source
AI summary
An integrated circuit device includes a substrate and a first electrically insulating layer on the substrate. An electrically conductive contact plug is provided, which extends at least partially through the first electrically insulating layer. The contact plug includes a protrusion having a top surface that is spaced farther from the substrate relative to a top surface of a portion of the first electrically insulating layer extending adjacent the contact plug. An electrically conductive line is provided with a terminal end, which extends on a first portion of the protrusion. A second electrically insulating layer is provided, which extends on a second portion of the protrusion and on the first electrically insulating layer. The second electrically insulating layer has a sidewall, which extends opposite a sidewall of the terminal end of the electrically conductive line.