Hydrophobic Coating for Capacitor Storage Node Stiction

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Solution Overview

Problem

During the fabrication of tall and thin capacitors, storage node structures can tip or topple due to lack of support, and spaces between adjacent nodes can act as capillaries, leading to stiction issues during etching and rinsing processes, causing electrical shorts.

Innovation Solution

Applying a hydrophobic and non-wetting material coating on the surfaces of the storage nodes to prevent stiction by increasing the contact angle with aqueous solutions, thereby reducing adhesion and maintaining structural integrity during processing stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If capacitors are made tall and thin to reduce footprint, then integration density is improved, but structural stability deteriorates causing nodes to tip or topple

Engineering Contradiction:

Improvefootprint of capacitorVSAvoidstructural stability of storage node

Core Design Contradiction:

Area of moving objectVSStability of the object's composition

Solution Approach 1:

The storage node is segmented into multiple sections with lattice structures inserted between them. These lattice structures act as internal support elements that divide the tall storage node into smaller, more stable segments, preventing tipping and toppling while maintaining the overall tall-and-thin configuration for reduced footprint.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Lattice structures are strategically placed at specific locations within the storage node where support is most needed. These localized support structures provide targeted structural reinforcement to prevent instability without adding overall volume, maintaining the compact footprint while improving local structural stability.

Inventive Principle:

Principle #3Local quality

2Productivity

If spaces between adjacent storage nodes are reduced to increase integration density, then productivity is improved, but stiction occurs during etching and rinsing processes

Engineering Contradiction:

Improveintegration densityVSAvoidelectrical isolation between nodes

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A hydrophobic coating is applied as an intermediary layer on the surfaces of storage nodes and lattice structures. This coating acts as a mediator that prevents aqueous solutions from adhering to the structures during etching and rinsing processes, eliminating capillary action and stiction forces that would otherwise cause nodes to stick together when spaced closely for high integration density.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The surface properties of the storage nodes and lattice structures are changed by applying a hydrophobic coating. This parameter change in surface energy and wettability prevents capillary action in the spaces between adjacent nodes, allowing close spacing for high integration density while maintaining electrical isolation by preventing stiction during wet processing.

Inventive Principle:

Principle #35Parameter changes

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 hydrophobic coating effectively prevents stiction between adjacent storage nodes, ensuring the structural stability of capacitors and preventing electrical shorts, while also providing insulation and support to maintain capacitor performance.

Implementation Method 1

Applying a hydrophobic and non-wetting material coating on the surfaces of the storage nodes to prevent stiction by increasing the contact angle with aqueous solutions

Methodology Applied

Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

spaces between adjacent storage nodes may function as capillaries during an etching process, and/or during a rinsing process, so that solution is drawn into such spaces

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Data Source

PatentUS8183157B2Method of forming capacitors, and methods of utilizing silicon dioxide-containing masking structures

Publication Date: 2012.05.22 MICRON TECHNOLOGY INC

AI summary

Some embodiments include methods of forming capacitors. Storage nodes are formed within a material. The storage nodes have sidewalls along the material. Some of the material is removed to expose portions of the sidewalls. The exposed portions of the sidewalls are coated with a substance that isn't wetted by water. Additional material is removed to expose uncoated regions of the sidewalls. The substance is removed, and then capacitor dielectric material is formed along the sidewalls of the storage nodes. Capacitor electrode material is then formed over the capacitor dielectric material. Some embodiments include methods of utilizing a silicon dioxide-containing masking structure in which the silicon dioxide of the masking structure is coated with a substance that isn't wetted by water.