DRAM Bit Line Transition Layer With Air Gaps for Lower Capacitance
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Solution Overview
Problem
The performance of Dynamic Random-Access Memory (DRAM) structures needs improvement, particularly in terms of reducing resistance and parasitic capacitance to enhance reading and writing speeds.
Innovation Solution
A method for manufacturing a DRAM structure involves forming bit line structures with a conductive layer, a transition layer, and a covering layer stacked sequentially, where the width of the transition layer is smaller than the conductive layer, and air gaps are formed on the top surface of the conductive layer and the side surfaces of the transition layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the covering layer is formed directly on the conductive layer, then the structural simplicity is maintained, but the resistance increases and performance deteriorates
Solution Approach 1:
The bit line structure is segmented into three distinct layers: conductive layer, transition layer, and covering layer. The transition layer is positioned between the conductive layer and covering layer, creating a segmented structure that reduces parasitic capacitance while maintaining structural integrity. This segmentation allows each layer to perform its specific function independently.
Solution Approach 2:
The transition layer is designed with local quality characteristics - it has a narrower width than the conductive layer, creating a tapered transition zone. This local variation in geometry optimizes the electrical properties at the interface between the conductive layer and covering layer, reducing resistance and parasitic capacitance in the critical transition region.
2Object-affected harmful factors
If the transition layer width is reduced, then parasitic capacitance decreases, but manufacturing precision requirements increase
Solution Approach 1:
The transition layer width variation is achieved in the lateral dimension rather than requiring extreme precision in the vertical dimension. By tapering the width in the lateral direction, the design reduces parasitic capacitance through geometric optimization while maintaining manufacturability through standard fabrication processes.
Data Source
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AI summary
Embodiments of the present disclosure belong to the technical field of semiconductor manufacturing, and involve a method for manufacturing a semiconductor structure and a semiconductor structure, which are used to improve performance of the semiconductor structure. The method for manufacturing the semiconductor structure includes: forming bit line structures on a substrate, each of the bit line structures including a conductive layer, a transition layer and a covering layer stacked sequentially, and a width of the transition layer being smaller than a width of the conductive layer; and forming air gaps on a top surface of the conductive layer and side surfaces of the transition layer. The air gaps can not only reduce influence of the covering layer on the conductive layer to prevent the resistance of the conductive layer from increasing, but also reduce the parasitic capacitance between the bit line structures and the surrounding structures thereof, thereby improving the performance of the semiconductor structure.