Semiconductor Bit Line Plug Structure for Parasitic Capacitance Reduction
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Solution Overview
Problem
As semiconductor devices become more integrated, the narrowing gap between pattern structures leads to increased parasitic capacitance, which deteriorates device performance.
Innovation Solution
A semiconductor device design featuring bit line structures with specific plug configurations, including a dual contact plug structure with varying line widths and spacers, is implemented to reduce parasitic capacitance. The method involves forming bit line structures, spacers, and plugs with precise dimensions and materials to optimize spacing and contact areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gap between pattern structures is narrowed to increase integration, then device integration is improved, but parasitic capacitance increases
Solution Approach 1:
A dual-contact plug structure with upper and lower plugs is introduced as an intermediary element between bit lines and storage nodes. The upper plug has a larger width than the lower plug, creating a tapered configuration that reduces parasitic capacitance by optimizing the transition area while maintaining electrical connectivity. This intermediary structure allows narrow bit line spacing without directly increasing capacitive coupling.
Solution Approach 2:
The plug structure exhibits local quality variation through its dual-contact design where the upper plug has a different width than the lower plug. This localized dimensional variation optimizes the electrical characteristics at different positions, reducing parasitic capacitance in the critical transition region while maintaining connection integrity at both the bit line and storage node interfaces.
2Object-generated harmful factors
If a dual contact plug structure with varying line widths is used to reduce parasitic capacitance, then parasitic capacitance is reduced, but device complexity increases
Solution Approach 1:
The contact plug is segmented into two distinct parts: an upper plug and a lower plug with different widths. This segmentation allows each part to be optimized for its specific function - the upper plug interfaces with the bit line while the lower plug connects to the storage node, reducing parasitic capacitance through the width variation without requiring complex three-dimensional structures.
Solution Approach 2:
The dual-contact plug structure utilizes dimensional variation in the lateral width dimension, where the upper plug has a larger width than the lower plug. This dimensional change approach simplifies the structure compared to complex vertical or angled configurations, achieving parasitic capacitance reduction through a straightforward width variation that can be implemented using standard semiconductor fabrication processes.
Data Source
AI summary
A semiconductor device includes a plurality of bit line structures formed to be spaced apart from each other over a semiconductor substrate, a first spacer formed on both sidewalls of each of the bit line structures, a lower plug formed between the bit line structures and in contact with the semiconductor substrate, an upper plug positioned over the lower plug and having a greater line width than the lower plug, a middle plug positioned between the lower plug and the upper plug and having a smaller line width than a line width of the lower plug, and a second spacer positioned between the middle plug and the first spacer, wherein the second spacer is thicker than the first spacer.