3D In-Silicon Battery Insulation via Dielectric Trench Spacers

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Solution Overview

Problem

Conventional 3D lithium ion batteries face commercial limitations due to leakage, dielectric breakdown, and parasitic cell degradation, which hinder their practicality in miniaturized, high-performance microbattery applications, especially in IoT and healthcare industries where solid-state energy storage with high gravimetric and areal capacity is required.

Innovation Solution

A 3D In-Silicon energy storage device is formed by creating a thick dielectric material layer on a silicon substrate, forming a 3D trench, and using a dielectric material spacer to isolate active energy storage materials, resulting in a silicon-encapsulated structure with robust insulation and reduced leakage and short-circuiting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional film encapsulation and packaging techniques are used for 3D microbatteries, then manufacturing control is maintained, but leakage and dielectric breakdown occur leading to commercial failure

Engineering Contradiction:

Improveleakage preventionVSAvoidpackaging structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The device is segmented into distinct functional regions: a 3D trench structure separates the active battery materials from the surrounding environment, with dielectric material lining the trench walls and field regions. This segmentation provides inherent leakage prevention without requiring complex external packaging layers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The active energy storage materials are nested within the 3D trench structure that is itself embedded in the silicon substrate. The dielectric material is nested along the trench sidewalls and field regions, creating a nested configuration where each layer provides protective and functional benefits without adding external packaging complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Quantity of substance

If 3D fabrication methods are used to increase energy density, then volumetric capacity improves, but manufacturing failures increase

Engineering Contradiction:

Improveenergy storage capacityVSAvoidfabrication reliability

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The dielectric material is deposited along the trench sidewalls and field regions before the active energy storage materials are placed in the trench. This preliminary action ensures that insulation and structural integrity are established prior to filling the trench with active materials, preventing manufacturing defects and ensuring fabrication reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention uses a thick dielectric material layer in the field regions and along trench sidewalls, changing the dielectric thickness parameter to provide robust insulation. This parameter change ensures adequate electrical isolation and mechanical stability, enabling reliable 3D fabrication with high energy storage capacity.

Inventive Principle:

Principle #35Parameter changes

3Volume of moving object

If miniaturization is pursued to reduce device footprint, then device size decreases, but energy storage density requirements increase

Engineering Contradiction:

Improvedevice footprintVSAvoidenergy storage capacity

Core Design Contradiction:

Volume of moving objectVSQuantity of substance

Solution Approach 1:

The invention transitions from 2D planar battery structures to 3D vertical trench structures. By utilizing the vertical dimension within the silicon substrate, the battery achieves high energy storage capacity in a minimized footprint. The 3D trench allows multiple active material layers to be stacked vertically, dramatically increasing volumetric energy density.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Reliability

If thick dielectric material patterning is implemented for robust insulation, then leakage is prevented, but processing steps increase

Engineering Contradiction:

Improveinsulation performanceVSAvoidmanufacturing throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The deposition of dielectric material along the trench sidewalls and field regions is merged into a single continuous processing step. This combined approach ensures uniform thick dielectric coverage throughout the 3D structure without requiring separate processing steps for different regions, maintaining high manufacturing throughput while achieving robust insulation performance.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11316154B2High throughput insulation of 3D in-silicon high volumetric energy and power dense energy storage devices

Publication Date: 2022.04.26 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A three dimensional (3D) In-Silicon energy storage device is provided by a method that includes forming a thick dielectric material layer on a surface of a silicon based substrate. A 3D trench is then formed into the dielectric material layer and the silicon based substrate, and thereafter a dielectric material spacer is formed, in addition to the dielectric remaining on the field of the substrate, as well as along a sidewall of the 3D trench, and on a first portion of a sub-surface of the silicon based substrate that is present at a bottom of the 3D trench. A second portion of the sub-surface of the silicon based substrate that is present in the 3D trench remains physically exposed. Active energy storage device materials can then be formed laterally adjacent to the dielectric material spacer that is within the 3D trench and on the dielectric material layer.