Contact Plug Protrusion Structure for Low-Resistance IC Interconnects
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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 MOSFETs are scaled down to achieve high integration, then device density increases, but operating characteristics deteriorate
Solution Approach 1:
The contact plug structure transitions from a conventional planar contact to a three-dimensional protruding structure that extends vertically above the interlayer insulating layer. This dimensional change increases the contact area between the conductive line and contact plug without expanding the lateral footprint, thereby improving electrical connectivity while maintaining high device density.
Solution Approach 2:
The contact plug is divided into distinct functional segments: a lower portion embedded in the first interlayer insulating layer for electrical connection, and an upper protrusion extending above the second interlayer insulating layer for enhanced contact area. This segmentation allows each portion to optimize its function while collectively improving overall device performance.
2Reliability
If contact area between conductive line and contact plug is increased, then resistance decreases, but device structure becomes more complex
Solution Approach 1:
The contact plug protrusion extends in the vertical dimension above the interlayer insulating layers, creating additional contact area with the conductive line without increasing lateral dimensions. This vertical extension reduces resistance and improves electrical connectivity while avoiding lateral complexity.
Solution Approach 2:
The contact plug structure is nested within the existing interlayer insulating layer architecture, with the protrusion fitting into the vertical space above the first interlayer insulating layer and alongside the second interlayer insulating layer. This nesting approach integrates the enhanced contact structure within the existing device layout without requiring additional lateral space or complex external structures.
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.