Multilayer Trench Capacitor Structure for Higher Capacitance Density
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Solution Overview
Problem
The capacitance of planar capacitors in semiconductor circuits is limited by the available area, necessitating a solution that enhances capacitance without increasing the capacitor's footprint.
Innovation Solution
The development of a multilayer trench capacitor that incorporates a capacitor trench filled with an in-trench capacitor material assembly comprising primary and complementary electrode layers and node dielectric layers, formed concurrently with an isolation trench, to achieve higher capacitance per unit area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If planar capacitor design is used, then manufacturing process is simple, but capacitance is limited by available area
Solution Approach 1:
The patent transitions from a planar (2D) capacitor design to a three-dimensional trench capacitor structure. By etching trenches into the substrate and stacking multiple electrode and dielectric layers vertically within the trench, the capacitor utilizes the third dimension (depth) to increase capacitance without expanding the lateral footprint on the semiconductor wafer.
Solution Approach 2:
The patent implements a nested structure where multiple electrode layers and dielectric layers are stacked concentrically within the trench. The first electrode layer, second electrode layer, and additional electrode layers are positioned at different depths within the same trench volume, creating a nested configuration that maximizes capacitance density within the available three-dimensional space.
2Quantity of substance
If multilayer trench capacitor is implemented, then capacitance per unit area increases, but device complexity increases
Solution Approach 1:
The capacitor structure is segmented into distinct functional layers: electrode layers (first, second, and additional electrode layers), dielectric layers (first and second dielectric layers), and conductive layers. This segmentation allows each layer to be optimized independently for its specific function while maintaining overall capacitance performance.
Solution Approach 2:
The trench structure serves multiple functions simultaneously: it provides the containment volume for the stacked electrode and dielectric layers, acts as the isolation structure between adjacent capacitors, and defines the vertical stacking geometry. This multi-functionality reduces the need for separate structural elements, thereby managing complexity.
Data Source
AI summary
A semiconductor structure includes a semiconductor substrate including a first trench and a second trench in an upper portion thereof, a trench isolation structure including a dielectric material and located in the first trench, and a capacitor including a doped substrate electrode layer located within the semiconductor substrate and underlying and laterally surrounding the second trench, and in-trench capacitor material assembly located within the second trench and including at least one primary electrode layer, at least one complementary electrode layer, and node dielectric layers. Each neighboring pair among the doped substrate electrode layer, the at least one primary electrode layer, and the at least one complementary electrode layer is spaced from each other by a respective one of the node dielectric layers.