Multi-Layer Trench Capacitor Structure for Higher Capacitance at Small Pitch
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Solution Overview
Problem
Integrated chips face a challenge in increasing capacitance without increasing the pitch, as reducing the pitch limits the area available for trenches and trench capacitors, thereby reducing capacitance.
Innovation Solution
The integration of multiple capacitors in a single trench, coupled in parallel, increases capacitance without expanding the pitch by using a dielectric structure with electrodes and insulative layers, where each capacitor is connected through contacts on opposite sides of the trench.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pitch is reduced to increase integration density, then the area available for trenches and trench capacitors decreases, but the capacitance decreases as a result
Solution Approach 1:
The single trench capacitor is segmented into multiple smaller capacitors arranged in parallel within the same trench structure. Each capacitor consists of alternating conductive layers and dielectric layers, creating multiple capacitor units that share the common trench space. This segmentation allows the total capacitance to be increased by summing the capacitances of individual units while maintaining the same pitch.
Solution Approach 2:
Multiple capacitor structures are nested within a single trench, with each capacitor unit containing conductive layers and dielectric layers arranged in a nested configuration. The conductive layers are positioned at different depths and lateral positions within the trench, creating a nested arrangement that maximizes the use of available space while maintaining electrical isolation through dielectric layers.
2Quantity of substance
If multiple capacitors are integrated in a single trench, then the capacitance increases, but the device complexity increases
Solution Approach 1:
The trench structure serves multiple functions simultaneously: it provides containment for multiple capacitor units, acts as an electrical isolation structure through the dielectric layers, and enables parallel connection of multiple capacitors to achieve increased total capacitance. The alternating conductive and dielectric layers perform multiple roles including electrode formation, insulation, and capacitance generation.
Solution Approach 2:
Multiple capacitor units are merged into a single integrated structure within the trench, sharing common dielectric materials and structural elements. The conductive layers from different capacitor units are merged to form continuous electrodes, while the dielectric layers provide unified insulation across all capacitor units, reducing the need for separate structural elements for each capacitor.
Data Source
AI summary
The present disclosure relates to an integrated chip including a dielectric structure over a substrate. A first capacitor is disposed between sidewalls of the dielectric structure. The first capacitor includes a first electrode between the sidewalls of the dielectric structure and a second electrode between the sidewalls and over the first electrode. A second capacitor is disposed between the sidewalls. The second capacitor includes the second electrode and a third electrode between the sidewalls and over the second electrode. A third capacitor is disposed between the sidewalls. The third capacitor includes the third electrode and a fourth electrode between the sidewalls and over the third electrode. The first capacitor, the second capacitor, and the third capacitor are coupled in parallel by a first contact on a first side of the first capacitor and a second contact on a second side of the first capacitor.