Semiconductor Capacitor Pillar Electrode with Supporter Pattern
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Solution Overview
Problem
As semiconductor devices continue to increase in capacity and integration, there is a challenge in maintaining sufficient capacitance in dynamic random-access memory (DRAM) devices, particularly in ensuring adequate contact area between the lower electrode of a capacitor and the dielectric film.
Innovation Solution
The semiconductor device incorporates a first contact plug on a substrate with a pillar-shaped lower electrode and a supporter pattern, where the dielectric film is formed on both the lower electrode and the supporter pattern, and an upper electrode is placed on the dielectric film, optimizing the contact area and reducing the aspect ratio to enhance capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact area between the lower electrode and dielectric film is increased to maintain capacitance, then the capacitance is improved, but the device complexity increases due to the need for additional supporter patterns and modified electrode structures
Solution Approach 1:
The lower electrode is extended in the thickness direction (vertical dimension) of the substrate to form a pillar shape, increasing the contact area with the dielectric film without expanding the planar footprint. This dimensional transition from 2D to 3D structure resolves the contradiction by achieving higher capacitance through vertical extension rather than horizontal expansion, thereby maintaining compact device geometry while improving electrical performance
Solution Approach 2:
A supporter pattern is introduced as an intermediary structure that provides mechanical support to the extended lower electrode pillar. The supporter pattern prevents the pillar from collapsing or deforming during fabrication and operation, enabling the vertical extension structure to be realized without compromising structural integrity. This intermediary element makes the complex 3D electrode structure manufacturable and reliable
2Reliability
If the lower electrode is extended in the thickness direction to increase contact area, then the capacitance is improved, but the aspect ratio of the electrode increases making processing more difficult
Solution Approach 1:
The supporter pattern acts as a structural intermediary that provides mechanical reinforcement to the extended lower electrode pillar. By positioning the supporter pattern at specific heights along the pillar, the structure gains intermediate support points that prevent collapse during deposition and etching processes. This enables the fabrication of high aspect ratio structures that would otherwise be impossible to manufacture with standard semiconductor processing techniques
Solution Approach 2:
The supporter pattern is strategically positioned at specific locations and heights along the lower electrode pillar, providing localized structural reinforcement only where needed. This selective support approach maintains the overall vertical extension for capacitance while adding complexity only in critical regions, thereby minimizing the impact on manufacturing precision and allowing standard fabrication processes to be used
3Productivity
If design rules are decreased to increase integration, then the productivity is improved, but the capacitance per cell deteriorates due to reduced contact area
Solution Approach 1:
By transitioning the lower electrode from a planar structure to a vertical pillar structure, the contact area with the dielectric film is increased in the thickness direction rather than the planar directions. This allows the electrode footprint to remain small (satisfying decreased design rules and high integration) while the vertical extension provides sufficient contact area for required capacitance values
Solution Approach 2:
The capacitor structure is segmented into distinct vertical layers: the lower electrode pillar, the dielectric film, and the upper electrode. This segmentation allows independent optimization of each layer - the lower electrode can be vertically extended to maximize contact area with the dielectric film, while the overall cell area is minimized through the vertical stacking approach, thereby achieving both high integration and sufficient capacitance
Data Source
AI summary
A semiconductor device includes a first contact plug on a substrate, a first lower electrode disposed on the first contact plug and extended in a thickness direction of the substrate, a first supporter pattern on the first lower electrode and including an upper surface and a lower surface, the upper surface of the first supporter pattern being higher than a top surface of the first lower electrode, a dielectric film on the first lower electrode, the upper surface of the first supporter pattern and the lower surface of the first supporter pattern and an upper electrode disposed on the dielectric film.