Deep Trench Capacitor Layout for Higher Capacitance Density
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Solution Overview
Problem
The reduction of electrode surface areas in capacitors due to miniaturization in semiconductor devices leads to a decrease in capacitance, necessitating an improvement in capacitance density.
Innovation Solution
A fabricating method that forms a deep trench capacitor structure by lining trenches with metal and dielectric layers, utilizing existing metal interconnect structures as electrodes, thereby increasing capacitance and density without requiring additional photomasks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If miniaturization is performed to increase integration density, then device integration density is improved, but electrode surface area of capacitors decreases resulting in reduced capacitance
Solution Approach 1:
The patent transitions from planar capacitor structures to three-dimensional deep trench capacitor structures. By etching deep trenches into the substrate and forming capacitor electrodes vertically along the trench walls, the design moves from two-dimensional surface area to three-dimensional volume utilization, dramatically increasing the effective electrode surface area within the same footprint area.
Solution Approach 2:
The patent embeds capacitor structures within the substrate by forming deep trenches and filling them with alternating layers of conductive and dielectric materials. The capacitor electrodes are nested vertically within the substrate depth, creating a nested configuration that maximizes capacitance within the available vertical space while maintaining high integration density.
2Quantity of substance
If deep trench capacitor structures are formed to increase capacitance density, then capacitance density is improved, but fabrication process complexity increases
Solution Approach 1:
The patent combines the formation of scribe line trenches and capacitor trenches into a single etching process. By designing the photomask pattern to include both scribe line locations and capacitor trench locations, both types of trenches are formed simultaneously in one step, reducing the total number of fabrication steps and simplifying the overall process.
Solution Approach 2:
The deep trench structure serves multiple functions: it acts as both a scribe line for substrate separation and as a capacitor structure for energy storage. This multi-functional design eliminates the need for separate capacitor formation processes and reduces overall device complexity while maintaining high capacitance density.
3Manufacturing precision
If additional photomasks are used to form capacitor structures, then manufacturing precision is improved, but fabrication time and cost increase
Solution Approach 1:
The patent merges the patterning of scribe lines and capacitor structures into a single photomask design. The photomask pattern simultaneously defines both the scribe line trenches and the capacitor trenches, allowing both features to be formed in one exposure and development cycle, thereby reducing fabrication time while maintaining precise positioning.
Solution Approach 2:
The photomask is designed in advance to include pre-defined patterns for both scribe lines and capacitor trenches. This preliminary design approach allows precise positioning of capacitor structures relative to scribe lines without requiring additional alignment steps, reducing both time and complexity.
Data Source
AI summary
A fabricating method of a semiconductor device includes performing a first patterning process to form a first trench in a substrate structure. The substrate structure includes a substrate and a compound semiconductor layer over the substrate. The first patterning process is performed such that the first trench passes through the compound semiconductor layer and exposes the substrate. The fabricating method further includes forming a capacitor structure in the first trench. Forming the capacitor structure includes: forming a first metal layer lining the first trench and in contact with the substrate; forming a first dielectric layer lining the first metal layer and in contact with the first metal layer; and forming a second metal layer lining the first dielectric layer and in contact with the first dielectric layer.