Shielded Deep Trench Capacitor Structure for EMI-Stable Output
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Solution Overview
Problem
Deep trench capacitors in semiconductor chips are susceptible to fluctuations in output voltage due to external electromagnetic radiation, which affects their stability.
Innovation Solution
A semiconductor structure with a conductive metallic substrate enclosure and a metallic interconnect enclosure structure is formed around deep trenches, incorporating a layer stack of metallic electrode layers and node dielectric layers, and a backside metal layer to create a metallic shield that blocks electromagnetic radiation, thereby stabilizing the output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If deep trench capacitors are used to provide high capacitance with small device footprint, then the capacitance density is improved, but the output voltage stability deteriorates due to susceptibility to external electromagnetic radiation
Solution Approach 1:
A metallic shield structure is introduced as an intermediary between the deep trench capacitor and external electromagnetic radiation. The shield comprises a conductive metallic substrate enclosure structure laterally surrounding the deep trenches, a backside metal layer contacting the backside surface of the substrate, and a metallic interconnect enclosure structure vertically extending between them, creating a Faraday cage effect that blocks electromagnetic radiation while allowing the capacitor to maintain high capacitance density
Solution Approach 2:
The metallic shield structure functions as a conductive enclosure shell that laterally surrounds and protects the deep trench capacitor structures. The substrate enclosure structure and interconnect enclosure structure form a flexible protective framework that adapts to the capacitor geometry while effectively blocking electromagnetic radiation from reaching the sensitive capacitor elements
2Reliability
If a metallic shield structure is added to block electromagnetic radiation, then the output voltage stability is improved, but the device complexity increases
Solution Approach 1:
The conductive metallic substrate enclosure structure serves multiple functions simultaneously: it acts as part of the capacitor electrode structure, provides lateral shielding against electromagnetic radiation, and serves as a structural support framework. The metallic interconnect enclosure structure similarly functions as both interconnect wiring and vertical shielding element, reducing the need for separate dedicated shield components
Solution Approach 2:
The metallic shield structure is nested within the existing capacitor architecture, with the conductive metallic substrate enclosure structure laterally surrounding the deep trenches and the metallic interconnect enclosure structure vertically extending between them. This nested configuration integrates shielding functionality into the existing device footprint without requiring additional external structures
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
The structure effectively reduces or eliminates the adverse effects of external electromagnetic radiation on the output voltage stability of deep trench capacitors, enhancing their performance.
Implementation Method 1
a metallic shield structure configured to block electromagnetic radiation from impinging into the trench capacitor structure
Data Source
AI summary
A moat trench laterally surrounding a device region is formed in a substrate. A conductive metallic substrate enclosure structure is formed in the moat trench. Deep trenches are formed in the substrate, and a trench capacitor structure is formed in the deep trenches. The substrate may be thinned by removing a backside portion of the substrate. A backside surface of the conductive metallic substrate enclosure structure is physically exposed. A backside metal layer is formed on a backside surface of the substrate and a backside surface of the conductive metallic substrate enclosure structure. A metallic interconnect enclosure structure and a metallic cap plate may be formed to provide a metallic shield structure configured to block electromagnetic radiation from impinging into the trench capacitor structure.