DRAM Cylindrical Capacitor Air-Gap Structure for Leakage Control
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Solution Overview
Problem
The challenge in manufacturing dynamic random access memory (DRAM) capacitors is the leakage caused by the penetration of boron particles into the dielectric material due to their small radius and the thermal process, which intensifies their diffusion, leading to increased capacitor leakage.
Innovation Solution
A manufacturing method that forms air gaps between adjacent cylindrical capacitors, reducing the boron-doped layer density and minimizing the diffusion of boron particles into the dielectric material by creating discontinuous parts in the second top electrode within the trenches, thereby preventing semiconductor structure leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a thinner dielectric material with higher dielectric constant is selected to increase capacitor density, then capacitor density is improved, but leakage current increases due to boron particle penetration
Solution Approach 1:
The patent introduces air gaps that segment the continuous boron-doped layer into discontinuous parts, physically blocking the diffusion path of boron particles toward the dielectric material while maintaining the overall capacitor structure and high-density configuration
Solution Approach 2:
The air gap acts as an intermediary barrier between the boron-doped layer and the dielectric material, preventing direct contact and diffusion of boron particles into the dielectric, thus reducing leakage current while preserving capacitor density
2Ease of manufacture
If continuous top electrode structure is used, then manufacturing simplicity is maintained, but boron particle diffusion into dielectric material increases
Solution Approach 1:
The continuous top electrode is segmented by introducing air gaps that create discontinuous regions, which block boron particle diffusion paths while maintaining overall structural integrity and manufacturability through standard fabrication processes
Solution Approach 2:
The harmful continuous pathway for boron diffusion is extracted by removing material to form air gaps, eliminating the diffusion channel while preserving the essential electrode functionality and maintaining manufacturing feasibility
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces the total amount of boron particles diffused into the dielectric material during thermal processing, effectively avoiding semiconductor structure leakage and enhancing electrical performance and reliability.
Implementation Method 1
the leakage caused by the penetration of boron particles into the dielectric material due to their small radius and the thermal process, which intensifies their diffusion
Data Source
AI summary
The present disclosure provides a manufacturing method of a semiconductor structure, and a semiconductor structure. The manufacturing method of a semiconductor structure includes: forming a plurality of cylindrical capacitors in an initial structure; removing part of the initial structure to form trenches, the trenches expose partial sidewalls of the cylindrical capacitors and a substrate of the initial structure; forming a dielectric layer, the dielectric layer at least covers an exposed surface of each of the cylindrical capacitors; forming a first top electrode, the first top electrode covers a surface of the dielectric layer; and forming a second top electrode, the second top electrode covers a surface of the first top electrode. In an axial direction of each of the cylindrical capacitors, the second top electrode formed in each of the trenches has a discontinuous part, and an air gap is formed in the discontinuous part of the second top electrode.