Self-Aligned Via Plug Structure for Low-Resistance IC Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As integration density of integrated circuits increases, manufacturing interconnection structures becomes more challenging due to smaller line widths, deteriorating conductive properties, and the need for thicker diffusion barrier layers, which can increase resistance and production costs, and complicate photoetching and filling of small-size contact holes.
Innovation Solution
An interconnection structure with self-aligned via plugs that electrically connect interconnection lines, using semiconductor materials like metal silicide or silicon-germanide, which reduces resistance and simplifies manufacturing by avoiding misalignment and using materials that are easier to fill and pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If line width is reduced to increase integration density, then more interconnection lines can be packed, but conductive properties deteriorate due to smaller grain size
Solution Approach 1:
The patent changes the material parameter from conventional metal (copper, aluminum) to metal silicide compound (cobalt silicide, tungsten silicide, molybdenum silicide). This material substitution maintains low resistance even at reduced line widths by utilizing the superior electrical properties of silicide compounds, which have lower resistivity and better grain boundary characteristics than pure metals at nanoscale dimensions.
2Manufacturing precision
If spacing between interconnection lines is increased to accommodate alignment errors, then manufacturing yield is improved, but production cost increases
Solution Approach 1:
The patent implements self-aligned via plug formation where the via plugs are automatically positioned at the intersections of first and second interconnection lines through a single patterning process. The via plug material layer is patterned together with the interconnection line material layer, creating automatic alignment without requiring additional alignment margins. This self-service alignment mechanism eliminates the need for increased spacing between interconnection lines, maximizing integration density while maintaining manufacturing yield.
Data Source
AI summary
An interconnection structure and a method of manufacturing the same, and an electronic device including the interconnection structure are provided. According to an embodiment, the interconnection structure includes: a first interconnection line at a first level, including at least a first portion extending along a first direction; a second interconnection line at a second level higher than the first level, including at least a second portion extending along a second direction crossing the first direction; a via plug disposed between the first portion of the first interconnection line and the second portion of the second interconnection line, and configured to electrically connect the first interconnection line and the second interconnection line, wherein the via plug includes a first pair of sidewalls respectively extending substantially parallel to corresponding sidewalls of the first portion and a second pair of sidewalls respectively extending substantially parallel to corresponding sidewalls of the second portion.