Lower Electrode Top Portion Width Reduction for Bridge Prevention
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Solution Overview
Problem
Integrated circuit (IC) devices face failures due to the bridge phenomenon between adjacent lower electrodes, especially when the aspect ratio of these electrodes is high and the distance between them is reduced, which affects the electrical characteristics and reliability of capacitors.
Innovation Solution
The IC device incorporates a lower electrode with a main and top portion, where the top portion has a reduced width and is supported by an upper support pattern with a seam portion, and a method of manufacturing that involves forming sacrificial spacers and support patterns to create a peripheral space, allowing for increased insulation distance between electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the aspect ratio of lower electrodes is increased to improve capacitance, then the capacitance of capacitors is improved, but the distance between adjacent lower electrodes is reduced causing bridge phenomenon and reliability failures
Solution Approach 1:
The upper support pattern is divided into multiple separate support patterns, each supporting an individual lower electrode. This segmentation creates isolated support structures that prevent the bridge phenomenon from spreading between adjacent electrodes while maintaining the necessary support for high aspect ratio electrodes.
Solution Approach 2:
The support structure is designed with different properties in different regions: the upper support pattern is positioned only at the top portions of lower electrodes, providing localized support where needed for high aspect ratio stability, while leaving the spaces between electrodes clear to prevent bridging. This local differentiation resolves the contradiction between needing support for tall electrodes and preventing bridges between them.
2Productivity
If the distance between lower electrodes is reduced to increase integration density, then the integration density is improved, but the bridge phenomenon occurs more frequently causing failures
Solution Approach 1:
By segmenting the support structure into discrete upper support patterns rather than a continuous support layer, the design enables closer spacing of lower electrodes while maintaining structural integrity. Each segmented support pattern is isolated to its specific electrode, preventing lateral connection between adjacent electrodes even at reduced distances.
Solution Approach 2:
The upper support pattern acts as an intermediary structure that provides mechanical support to lower electrodes without creating conductive or physical bridges between them. This intermediary support enables high integration density by allowing electrodes to be positioned closer together while still maintaining device reliability through prevention of the bridge phenomenon.
3Reliability
If the height of lower electrodes is increased to improve capacitance, then the capacitance is improved, but the manufacturing precision becomes more difficult to control
Solution Approach 1:
The upper support pattern is formed in advance before the lower electrodes are fully processed, providing a pre-established support framework. This preliminary action allows subsequent electrode formation processes to proceed with better precision control, as the support structure is already in place to guide and stabilize the high aspect ratio electrode formation.
Solution Approach 2:
Support is applied locally at the top portions of lower electrodes rather than uniformly throughout the entire electrode structure. This localized support at critical regions enables better control of manufacturing precision for high aspect ratio electrodes, as the support is concentrated where it is most needed for stability during fabrication processes.
Data Source
AI summary
An integrated circuit (IC) device includes a lower electrode including a main portion having a sidewall with at least one step portion, and a top portion having a width less than that of the main portion in a lateral direction. An upper support pattern contacts the top portion of the lower electrode. The upper support pattern includes a seam portion. To manufacture an IC device, a mold pattern and an upper sacrificial support pattern through which a plurality of holes pass are formed on a substrate. A plurality of lower electrodes are formed inside the plurality of holes. A peripheral space is formed on the mold pattern. An enlarged peripheral space is formed by reducing a width and a height of the top portion. An upper support pattern is formed to fill the enlarged peripheral space.