Columnar Capacitor Structure With Support Cores to Prevent Collapse
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Solution Overview
Problem
In the formation of high-aspect-ratio double-sided capacitors, the hollow capacitance column is prone to instability and collapse during etching, leading to electrical instability of the inner-layer capacitance, which affects the yield of semiconductor structures.
Innovation Solution
A method is introduced to form semiconductor structures with stable supporting structures on a semiconductor substrate, where discrete conducting layers are used, and capacitor openings are formed between these structures. Lower electrodes are electrically connected to the conducting layers, covered by a capacitor dielectric layer, and topped with an upper electrode, eliminating the need for high-aspect-ratio capacitor holes during etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If high-aspect-ratio capacitor holes are formed by etching to create hollow capacitance columns, then capacitor aspect ratio is improved, but the hollow capacitance column becomes unstable and prone to collapse during etching
Solution Approach 1:
The patent applies preliminary action by forming solid supporting structures and lower electrodes before forming the capacitor dielectric layer. The supporting structures are prepared in advance to provide mechanical support, preventing collapse during subsequent etching and formation processes. This advance preparation ensures structural integrity while enabling high-aspect-ratio capacitor formation.
Solution Approach 2:
The patent introduces solid supporting structures as intermediary elements between the substrate and the capacitor dielectric layer. These supporting structures act as mediators that provide mechanical support to the capacitor structure, enabling high-aspect-ratio formation without collapse. The supporting structures are subsequently removed after serving their supporting function, having fulfilled their intermediary role.
2Length of stationary object
If hollow capacitance columns are formed by etching, then capacitor aspect ratio is increased, but electrical instability of inner-layer capacitance occurs
Solution Approach 1:
The patent forms solid lower electrodes and supporting structures before forming the capacitor dielectric layer. This preliminary action ensures that the capacitor structure maintains electrical stability during the etching and formation processes. The solid lower electrodes provide a stable electrical foundation, preventing the electrical instability that would otherwise occur with hollow capacitance columns.
Solution Approach 2:
The patent employs composite structures combining supporting structures, lower electrodes, and capacitor dielectric layers. This composite approach integrates multiple functional elements that work together to maintain both mechanical stability and electrical stability during high-aspect-ratio capacitor formation, overcoming the limitations of simple hollow column structures.
3Quantity of substance
If double-sided capacitors are formed to increase capacitance, then capacitor capacitance is improved, but process complexity and cost increase
Solution Approach 1:
The patent segments the capacitor formation process into distinct stages: forming supporting structures, forming lower electrodes, forming capacitor dielectric layers, and forming upper electrodes. This segmentation allows each component to be optimized independently and simplifies the overall process control, reducing complexity while maintaining the ability to form high-capacitance structures.
Solution Approach 2:
The patent transitions from planar capacitor formation to three-dimensional columnar capacitor structures. By utilizing the vertical dimension to create high-aspect-ratio capacitors, the patent increases capacitance without requiring more complex multi-sided structures. This dimensional change allows simple sequential processing steps to achieve high capacitance values.
Data Source
AI summary
A method for forming a semiconductor structure includes providing a semiconductor substrate, which at least includes discrete conducting layers in the semiconductor substrate; forming discretely arranged supporting structures on the semiconductor substrate, capacitor openings being included between the supporting structures; forming lower electrodes on sidewalls of the supporting structures, the lower electrodes being electrically connected with the conducting layers; forming a capacitor dielectric layer covering tops of the supporting structures, sidewalls of the lower electrodes, and bottoms of the capacitor openings; and forming an upper electrode covering the capacitor dielectric layer, to form capacitor structures.