Self-Aligned Conductive Lines and Vias for Void Reduction
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Solution Overview
Problem
The challenge in semiconductor device manufacturing is to form reliable devices at increasingly smaller sizes, as feature sizes decrease and fabrication processes become more complex.
Innovation Solution
The process involves forming self-aligned conductive features by using dummy elements with a line pattern to assist in the formation of conductive lines, followed by modifying the dummy elements to have a via pattern, and then removing them to create self-aligned via holes for conductive vias.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency increases and costs decrease, but fabrication process complexity and difficulty increase
Solution Approach 1:
The patent applies preliminary action by forming dummy elements before the actual conductive lines, which then serve as alignment references for subsequent via hole formation. This pre-positioned structure enables self-alignment in later processing steps, simplifying the overall fabrication process despite scaling to smaller features.
Solution Approach 2:
The dummy elements act as intermediary structures that facilitate the self-alignment process. These temporary features serve as mediators between the conductive lines and via holes, enabling precise alignment without requiring complex alignment procedures at each subsequent step.
2Productivity
If feature sizes decrease to increase functional density, then more devices fit per chip area, but manufacturing reliability becomes more difficult to achieve
Solution Approach 1:
The patent implements self-service through self-aligned via holes that automatically position themselves relative to the conductive lines using the dummy elements as references. This self-alignment mechanism ensures consistent positioning accuracy without requiring additional alignment steps, maintaining reliability as features scale down.
3Ease of manufacture
If conventional alignment methods are used for conductive vias, then manufacturing process is simpler, but voids form and quality of conductive features deteriorates
Solution Approach 1:
The patent replaces conventional mechanical alignment systems with a self-aligned approach using dummy elements as positional references. This substitution eliminates the need for complex alignment machinery and procedures while achieving superior positioning accuracy, thereby improving conductive feature quality without sacrificing ease of manufacture.
Data Source
AI summary
A semiconductor device structure is provided. The semiconductor device structure includes a semiconductor substrate and a conductive line over the semiconductor substrate. The conductive line has a barrier region surrounding an inner portion of the conductive line, and the barrier region has a greater dopant concentration than the inner portion. The semiconductor device structure also includes a conductive via on the conductive line. The semiconductor device structure further includes a dielectric layer over the semiconductor substrate. The dielectric layer surrounds the conductive line and the conductive via.