Layered Lower Electrode Structure to Prevent DRAM Capacitor Collapse
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of semiconductor devices poses a risk of collapse for lower electrodes with high aspect ratios during manufacturing due to their structural vulnerability.
Innovation Solution
Incorporating an inner protective layer and an outer protective layer, specifically using titanium silicon nitride and titanium oxide respectively, to enhance the structural integrity of the lower electrodes, along with a conductive layer and supporter patterns to prevent bending or collapsing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the lower electrode is miniaturized to achieve high integration, then the capacitance density increases, but the lower electrode becomes vulnerable to collapsing during manufacturing
Solution Approach 1:
The lower electrode is segmented into multiple functional layers: an inner protective layer (titanium silicon nitride) providing structural support, a conductive layer (titanium nitride) providing electrical functionality, and an outer protective layer (titanium oxide) providing chemical stability. This segmentation allows each layer to optimize for its specific function while collectively preventing collapse
Solution Approach 2:
The lower electrode uses composite material structure combining titanium silicon nitride (inner protective layer), titanium nitride (conductive layer), and titanium oxide (outer protective layer). Each material contributes unique properties: mechanical strength from TiSiN, electrical conductivity from TiN, and chemical stability from TiO2, creating a composite structure that prevents collapse while maintaining miniaturization
2Area of stationary object
If the lower electrode size is reduced, then the device footprint decreases, but the aspect ratio increases making the electrode prone to bending
Solution Approach 1:
The lower electrode structure applies local quality by providing enhanced mechanical support specifically at critical regions through the inner protective layer (titanium silicon nitride) which has high mechanical strength. This allows the electrode to maintain thin profile for miniaturization while having localized reinforcement where needed to prevent bending
Solution Approach 2:
The electrode is divided into functional segments with the inner protective layer providing structural reinforcement, the conductive layer providing electrical function, and the outer protective layer providing environmental stability. This segmentation allows optimization of each segment for its specific purpose
Data Source
AI summary
A semiconductor device includes a landing pad on a substrate, a lower electrode on the landing pad, the lower electrode including an outer protective layer, a conductive layer between opposing sidewalls of the outer protective layer, and an inner protective layer between opposing sidewalls of the conductive layer, a first supporter pattern on a side surface of the lower electrode, the first supporter pattern including a supporter hole, a dielectric layer on a surface of each of the lower electrode and the first supporter pattern, and an upper electrode on the dielectric layer. The outer protective layer includes titanium oxide, the conductive layer includes titanium nitride, and the inner protective layer includes titanium silicon nitride. In a horizontal cross-sectional view, the outer protective layer has an arc shape that extends between the dielectric layer and the conductive layer.