Embedded Interdigitated Capacitor Structure for Power Density
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Solution Overview
Problem
Existing capacitor technologies face challenges in integrating high-capacitance components directly into semiconductor devices without compromising mechanical stability and performance, particularly in high-frequency applications.
Innovation Solution
A multi-layer substrate-based capacitor design is fabricated with interdigitated fingers and a dielectric layer, where the fingers are formed via deep trench etching, and a dielectric material is used to enhance capacitance and mechanical support, allowing integration into semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-capacitance components are integrated directly into semiconductor devices, then power density and performance are improved, but mechanical stability and structural integrity deteriorate
Solution Approach 1:
The substrate is segmented into multiple thin layers (first substrate layer, second substrate layer, third substrate layer) with the capacitor structure embedded between them. This segmentation distributes mechanical stress and maintains structural integrity while allowing high-capacitance integration. The interdigitated fingers are also segmented into multiple sets (first set, second set, third set) arranged in different planes, which helps maintain mechanical stability while increasing capacitance density.
Solution Approach 2:
The capacitor structure utilizes three-dimensional interdigitated fingers extending in multiple directions (first direction, second direction, third direction) rather than simple planar plates. This dimensional expansion increases the effective capacitance area without proportionally increasing the footprint, thereby improving power density while maintaining mechanical stability through efficient space utilization.
2Quantity of substance
If interdigitated fingers are used to increase capacitance, then capacitance value is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The substrate layers serve multiple functions: they provide mechanical support, electrical isolation, and structural framework for the capacitor. The dielectric material between fingers serves both as electrical insulation and as part of the capacitance-forming structure. This multi-functionality reduces the need for additional separate components and simplifies the overall device architecture despite the complex interdigitated geometry.
Solution Approach 2:
The capacitor structure is nested within the multi-layer substrate architecture, with interdigitated fingers positioned between substrate layers. The first, second, and third sets of fingers are nested in different spatial planes, allowing compact integration of high capacitance value within a confined volume without excessive device complexity.
3Manufacturing precision
If deep trench etching is used to form interdigitated fingers, then manufacturing precision is improved, but fabrication difficulty and process complexity increase
Solution Approach 1:
The substrate is pre-formed into multiple thin layers with appropriate thicknesses before the deep trench etching process. This preliminary structuring provides better mechanical support during the etching process and enables more precise formation of the interdigitated fingers. The pre-defined layer architecture guides the subsequent fabrication steps and improves overall manufacturing precision.
Solution Approach 2:
The substrate is divided into multiple thin layers with controlled thicknesses (first thickness, second thickness, third thickness) to optimize the etching process. This parameter change in substrate structure enables better control over finger formation precision while reducing the mechanical stress and fabrication difficulty associated with deep trench etching in thick monolithic substrates.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables higher power densities and improved mechanical stability by embedding capacitors within semiconductor devices, enhancing performance and reducing the need for discrete capacitors.
Implementation Method 1
The dielectric layer is disposed between the first and second set of fingers. The first capacitor terminal is coupled to the first set of fingers. The second capacitor terminal is coupled to the second set of fingers.
Implementation Method 2
forming a dielectric layer in interstitial spaces between the first and second sets of fingers to capacitively couple the first and second sets of fingers
Data Source
AI summary
In a described example, an apparatus can include a multi-layer substrate and a capacitor device. The multi-layer substrate has a first surface and a second surface. The capacitor device is on the second surface of the multi-layer substrate. The capacitor device can include a conductive substrate layer, a dielectric layer, a first capacitor terminal, and a second capacitor terminal. The conductive substrate layer can include a first set of fingers and a second set of fingers. The first set of fingers is interdigitated with the second set of fingers. The dielectric layer is between the first and second set of fingers. The first capacitor terminal is coupled to the first set of fingers. The second capacitor terminal is coupled to the second set of fingers.