Trench Capacitor Lateral Protrusions for High Capacitance
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Solution Overview
Problem
Conventional trench capacitors with solely vertical sidewalls have limited surface areas and capacitance values, requiring increased depth to achieve greater capacitance, which in turn increases manufacturing costs and device size.
Innovation Solution
The semiconductor device incorporates a trench capacitor with lateral protrusions that fill lateral recesses in a dielectric structure, increasing surface area without increasing trench depth, thereby enhancing capacitance without elevating manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the trench depth is increased to achieve greater capacitance, then the capacitance value is improved, but the manufacturing cost and device size increase
Solution Approach 1:
The patent transitions from a conventional vertical-sided trench to a trench with lateral protrusions that extend horizontally into the substrate. This dimensional change allows the capacitor to gain additional surface area and capacitance by utilizing the lateral dimension rather than increasing vertical depth, thereby resolving the contradiction between achieving higher capacitance and maintaining compact device size.
Solution Approach 2:
The lateral protrusions are formed by nesting additional conductive layers and dielectric materials within the existing trench structure. The protrusions extend from the main trench body into the surrounding substrate, effectively nesting capacitor elements within the available space without requiring increased trench depth, thus maintaining manufacturing cost while improving capacitance.
2Reliability
If the trench depth is increased to achieve greater capacitance, then the capacitance value is improved, but the device size increases
Solution Approach 1:
The invention utilizes lateral protrusions that extend horizontally from the trench into the substrate, converting vertical depth requirements into lateral expansion. This dimensional transformation allows the capacitor to achieve greater capacitance through increased surface area in the lateral dimension while maintaining a compact vertical profile, thereby improving capacitance without significantly increasing overall device volume.
Solution Approach 2:
The lateral protrusions create localized regions of increased capacitance density within the substrate. By concentrating capacitor structures in specific lateral zones rather than uniformly increasing trench depth throughout, the design achieves higher overall capacitance while maintaining compact device dimensions through strategic local expansion.
3Reliability
If the trench depth is increased to achieve greater capacitance, then the capacitance value is improved, but the manufacturing cost increases
Solution Approach 1:
The lateral protrusion structure achieves greater capacitance through horizontal extension rather than vertical deepening. This approach utilizes standard trench fabrication processes that can be adapted to create protrusions using existing photolithography and deposition techniques, avoiding the need for specialized deep-trench equipment and processes, thereby maintaining manufacturing cost while improving capacitance.
Solution Approach 2:
The lateral protrusion structure serves multiple functions: it increases capacitance surface area, maintains compatibility with standard semiconductor fabrication processes, and provides a scalable design that can be integrated into existing manufacturing workflows. This multi-functionality allows the design to achieve improved capacitance without proportionally increasing manufacturing complexity or cost.
Data Source
AI summary
Various embodiments of the present application are directed towards a semiconductor device comprising a trench capacitor, the trench capacitor comprising a plurality of lateral protrusions. In some embodiments, the trench capacitor comprises a dielectric structure over a substrate. The dielectric structure may comprise a plurality of dielectric layers overlying the substrate. The dielectric structure may comprise a plurality of lateral recesses. In some embodiments, the plurality of lateral protrusions extend toward and fill the plurality of lateral recesses. By forming the trench capacitor with the plurality of lateral protrusions filling the plurality of lateral recesses, the surface area of the capacitor is increased without increasing the depth of the trench. As a result, greater capacitance values may be achieved without necessarily increasing the depth of the trench and thus, without necessarily increasing the size of the semiconductor device.