Co-processed E-fuse with MIM Capacitor for Low-Power Trimming

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Solution Overview

Problem

Current BEOL e-fuses in semiconductor chips require higher power for programming due to limitations in lithographic processing, leading to potential damage and the need for surrounding fuse protection, which complicates their integration with MIM capacitors.

Innovation Solution

An e-fuse element is formed integral with the MIM capacitor plate electrode and co-processed during MIM capacitor fabrication at the BEOL metallization stack level, eliminating the need for extra lithographic masks and processing steps, allowing for low-power programming and integration within the MIM capacitor structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If Cu wire or via is used as e-fuse element in current BEOL processing, then the e-fuse can be formed with existing lithographic processes, but the e-fuse cannot be made smaller than the minimum line width, requiring higher power for programming

Engineering Contradiction:

Improvee-fuse sizeVSAvoidprogramming power

Core Design Contradiction:

Length of moving objectVSPower

Solution Approach 1:

The patent merges the e-fuse element formation with the MIM capacitor plate electrode formation by co-processing them during the same lithographic and deposition steps. This integration allows the e-fuse to be formed at the MIM capacitor level where smaller dimensions are achievable, enabling reduced e-fuse size without requiring additional lithographic masks or processing steps that would increase complexity and power requirements

Inventive Principle:

Principle #5Merging (Combining)

2Power

If e-fuse is made smaller to reduce power, then programming power is reduced, but the smaller e-fuse requires higher precision lithographic processing

Engineering Contradiction:

Improveprogramming powerVSAvoidlithographic precision

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

By combining e-fuse formation with MIM capacitor plate electrode formation in the same processing sequence, the patent leverages the existing high-precision lithographic steps already required for capacitor fabrication. This approach achieves small e-fuse dimensions with reduced power requirements while maintaining manufacturing feasibility through process integration rather than requiring separate high-precision lithographic steps

Inventive Principle:

Principle #5Merging (Combining)

3Power

If e-fuse is programmed with higher power, then programming is more effective, but potential severe damage is inflicted requiring surrounding fuse protection

Engineering Contradiction:

Improveprogramming powerVSAvoiddamage to surrounding structures

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The integration of e-fuse with MIM capacitor structure allows the e-fuse to benefit from the capacitor's inherent protection structures and the co-processed nature of the device. The shared processing and structural integration enable effective programming while reducing the need for additional surrounding fuse protection that would be required in conventional separate e-fuse implementations

Inventive Principle:

Principle #5Merging (Combining)

4Object-affected harmful factors

If e-fuse is built at lower metal levels to avoid damage, then protection is provided, but the spacing has higher demand for signal/power wiring

Engineering Contradiction:

Improveprotection from damageVSAvoidwiring spacing requirements

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent moves the e-fuse formation from lower metal levels to the MIM capacitor level (a higher vertical dimension in the BEOL stack). This dimensional transition allows the e-fuse to be positioned where it can share processing steps with the capacitor while maintaining adequate spacing for signal and power wiring, thereby reducing wiring complexity compared to lower-level implementations

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 solution enables efficient, low-power programming and integration of e-fuse elements with MIM capacitors, reducing the risk of damage and optimizing chip design by utilizing existing processing steps, thus enhancing semiconductor chip performance and reliability.

Implementation Method 1

a MIM capacitor is formed at a BEOL metallization stack and the metallization stack co-processing steps form an e-fuse to as part of the MIM capacitor

Methodology Applied

Scientific EffectDeposition: Deposition (physical)

Data Source

PatentUS11257750B2E-fuse co-processed with MIM capacitor

Publication Date: 2022.02.22 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

Metal e-fuse structure formed during back-end-of-line during processing and integral with on-chip metal-insulator-metal (MIM) capacitor (MIMcap). The metal e-fuse structures are extensions of MIMcap electrodes and are structured to isolate BEOL MIM capacitors for trimming and/or to isolate shorted or rendered highly leaky due to in process, or service induced defects. In one embodiment, the method incorporates the integral, co-processed metal e-fuse in series between the MIM capacitor and an active circuit. When a high current passes through the e-fuse element, the e-fuse element is rendered highly resistive or electrically open thereby disconnecting the MIM capacitor or electrode plate from the active circuitry. The e-fuse structure may comprise a thin neck portion(s) or zig-zag neck portion that extend from an MIMcap electrode away from the MIMcap between two inter-level interconnect via structures.