Pillar-Type DRAM Storage Node with Inner Supporter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In sub-50-nm DRAM devices, the cylindrical storage node is challenging to implement due to insufficient space for insulation between adjacent nodes, leading to defects from wet etchant penetration and shear stress-induced bending, which affects charge capacity and reliability.
Innovation Solution
A capacitor with a pillar-type storage node is developed, featuring a supporter filling the inner crevice to prevent wet etchant penetration and shear stress, along with a dielectric and plate node structure to enhance insulation and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a cylindrical storage node is used to increase charge capacity, then capacitance is improved, but insulation space between adjacent nodes becomes insufficient
Solution Approach 1:
The storage node transitions from a two-dimensional planar structure to a three-dimensional pillar structure with height dimension added. This vertical extension increases charge capacity while the pillar geometry with rounded corners maintains adequate horizontal insulation spacing between adjacent nodes, resolving the contradiction between capacitance and insulation space.
Solution Approach 2:
The storage node employs a pillar structure with rounded corners and curved surfaces instead of sharp edges. This curvature design reduces stress concentration points that would otherwise compromise structural integrity and insulation, while maintaining the increased charge capacity provided by the three-dimensional geometry.
2Area of stationary object
If a pillar type storage node is formed to secure insulation space, then insulation is improved, but minute crevices cause wet etchant penetration and defects
Solution Approach 1:
The corner radius parameter of the pillar structure is optimized to balance two competing requirements: large enough to prevent minute crevice formation and etchant penetration, but small enough to maintain adequate insulation space between adjacent nodes. This parameter adjustment resolves the contradiction between insulation and defect prevention.
3Area of stationary object
If a pillar type storage node is formed to secure insulation space, then insulation is improved, but shear stress causes storage node bending
Solution Approach 1:
The pillar structure employs rounded corners and curved surfaces that distribute shear stress uniformly across the structure, eliminating stress concentration at sharp edges. This curvature design prevents bending and maintains storage node stability while preserving the insulation benefits of the pillar geometry.
Solution Approach 2:
The corner radius parameter is optimized to provide sufficient structural reinforcement against shear stress-induced bending, while maintaining the insulation spacing requirements. This parameter adjustment resolves the contradiction between insulation space and structural stability.
Data Source
AI summary
A capacitor includes a pillar-type storage node, a supporter disposed entirely within an inner empty crevice of the storage node, a conductive capping layer over the supporter and contacting the storage node so as to seal an entrance to the inner empty crevice, a dielectric layer over the storage node, and a plate node over the dielectric layer.