Supercritical Drying for Semiconductor Capacitor Column Stability
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Solution Overview
Problem
As semiconductor devices, particularly capacitor structures in memory devices, face challenges with increasing aspect ratios, there is a risk of wobbling, bending, and twisting during fabrication, leading to potential short circuit faults due to surface tension and capillary forces during drying processes.
Innovation Solution
A method involving the formation of a nitride support structure at mid-height within the capacitor column, followed by supercritical drying using compounds like CO2, to mitigate the effects of surface tension and capillary forces, thereby reducing the risk of structural instability and short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the aspect ratio of capacitor structures is increased to achieve higher density, then the storage capacity is improved, but the structural stability deteriorates due to wobbling, bending, and twisting during fabrication
Solution Approach 1:
The capacitor structure is divided into multiple segments with support structures positioned at intermediate heights (e.g., first support structure at 30-70% height, second support structure at different height). This segmentation provides mechanical reinforcement along the column, preventing wobbling and bending while maintaining the high aspect ratio needed for increased storage capacity.
Solution Approach 2:
Support structures are strategically placed at specific locations (mid-height and other intermediate positions) rather than uniformly distributed. This local reinforcement approach provides targeted structural stability where most needed, allowing the capacitor columns to maintain their high aspect ratio without compromising overall structural integrity during fabrication.
2Ease of manufacture
If conventional drying processes are used, then the manufacturing simplicity is maintained, but surface tension and capillary forces cause structural instability and potential short circuits
Solution Approach 1:
The drying process parameters are changed by using supercritical drying conditions (temperature and pressure above critical point of CO2) instead of conventional atmospheric drying. This parameter change eliminates surface tension and capillary forces that cause structural instability, while the use of CO2 as the supercritical fluid maintains manufacturing feasibility. The gradual pressure release protocol further ensures reliable drying without compromising structural integrity.
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
The approach effectively minimizes the probability of wobbling and twisting, preventing short circuit faults and enhancing the stability and capacitance of capacitor structures, allowing for higher density and reliability in memory devices.
Implementation Method 1
performing supercritical drying on the capacitor column structure. The supercritical drying may reduce a probability of the capacitor column structure wobbling, bending, and/or twisting
Implementation Method 2
The supercritical drying may reduce a probability of the capacitor column structure wobbling, bending, and/or twisting
Implementation Method 3
A method may include patterning a surface of a semiconductor substrate to have a first silicate material, a nitride material over the first silicate material, and a second silicate material over the nitride material
Data Source
AI summary
Methods, apparatuses, and systems related to semiconductor processing (e.g., of a capacitor support structure) are described. An example method includes patterning a surface of a semiconductor substrate to have a first silicate material, a nitride material over the first silicate material, and a second silicate material over the nitride material. The method further includes removing the first silicate material and the second silicate material and leaving the nitride material as a support structure for a column formed from a capacitor material. The method further includes performing supercritical drying on the column, after removal of the first and second silicate materials, to reduce a probability of the column wobbling relative to otherwise drying the column after the removal of the first and second silicate materials.