Metal-Insulator-Metal Capacitor Using Block Copolymer Self-Assembly

Solution Overview

Problem

The existing processes for fabricating metal-insulator-metal capacitors require additional mask steps to increase capacitance per unit area, leading to increased process complexity and potential plasma damage at the metal-dielectric interfaces.

Innovation Solution

The use of self-assembling block copolymers to define patterning regions without the need for extra masking steps, allowing for the creation of MIMCAP structures with increased surface area and capacitance through the formation of high and low domains and subsequent topographical features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If additional mask steps are used to increase capacitance per unit area, then capacitance per unit area is improved, but process complexity increases

Engineering Contradiction:

Improvecapacitance per unit areaVSAvoidprocess complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The block copolymer system performs self-patterning through spontaneous self-assembly, eliminating the need for additional photomask steps. The system serves itself by using the inherent phase separation of block copolymers to create the desired topographical features that increase capacitance without requiring external patterning intervention

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention changes the physical and chemical parameters of the substrate surface by introducing block copolymer layers with specific properties (composition, molecular weight, solvent quality) that drive self-assembly into desired patterns, thereby achieving increased capacitance through parameter optimization rather than process complexity

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If additional mask steps are used to increase capacitance per unit area, then capacitance per unit area is improved, but fabrication cost increases

Engineering Contradiction:

Improvecapacitance per unit areaVSAvoidfabrication cost

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The block copolymer system performs self-patterning through spontaneous self-assembly, eliminating the need for additional photomask steps. The system serves itself by using the inherent phase separation of block copolymers to create the desired topographical features that increase capacitance without requiring external patterning intervention

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The block copolymer layers act as temporary sacrificial structures that are eventually removed after transferring their pattern to the underlying layers. These disposable self-assembled structures enable complex patterning at low cost since the copolymers themselves are inexpensive materials compared to multiple photomask fabrication and processing steps

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Quantity of substance

If additional mask steps are used to increase capacitance per unit area, then capacitance per unit area is improved, but plasma damage increases

Engineering Contradiction:

Improvecapacitance per unit areaVSAvoidplasma damage

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The block copolymer system performs self-patterning through spontaneous self-assembly, eliminating the need for additional photomask steps. The system serves itself by using the inherent phase separation of block copolymers to create the desired topographical features that increase capacitance without requiring external patterning intervention

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The block copolymer pattern is formed in advance before any plasma etching or damage-prone processes. This preliminary self-assembly creates a protective template that guides subsequent processing, allowing the metal-dielectric interfaces to be formed without exposure to additional plasma damage from extra mask steps

Inventive Principle:

Principle #10Preliminary action

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

This approach reduces process complexity, minimizes plasma damage, and effectively increases capacitance per unit area without the need for additional patterning steps, thereby improving the efficiency and yield of capacitor fabrication.

Implementation Method 1

The use of self-assembling block copolymers to define patterning regions without the need for extra masking steps

Methodology Applied

Scientific EffectSelf-assembly: Self-Assembly

Data Source

PatentUS10978550B2Efficient metal-insulator-metal capacitor

Publication Date: 2021.04.13 ADEIA SEMICONDUCTOR SOLUTIONS LLC

AI summary

A capacitor includes a stack. The stack has a first metallic layer formed over a substrate, an insulator formed over the first metallic layer, and a second metallic layer formed over the insulator. The first metallic layer has at least one high domain and at least one low domain, where a surface of the substrate in the at least one low domain has a height that is lower than a surface of the substrate in the at least one high domain.