Semiconductor Interconnect Manganese Segregation Electromigration

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Solution Overview

Problem

Copper interconnects in semiconductor devices are prone to electromigration, leading to device malfunction and a limited lifespan, necessitating the use of barrier layers to mitigate this issue effectively.

Innovation Solution

A method of manufacturing semiconductor structures involves forming a seed material with copper and manganese (0.10 at % to 0.40 at %) and moving manganese to the interface between the seed material and the barrier layer, creating a manganese-rich layer that enhances the semiconductor's lifespan by forming manganese or manganese oxide, thereby improving the structure's resistance to electromigration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a barrier layer is deposited into the vias or trenches to protect copper from electromigration, then the reliability of the semiconductor device is improved, but the lifespan of the semiconductor device reaches an upper limit and cannot be extended

Engineering Contradiction:

Improveprotection from electromigrationVSAvoidlifespan of semiconductor device

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies local quality by creating a manganese-rich layer specifically at the interface between the seed material and barrier layer, rather than uniformly distributing manganese throughout the copper interconnect. This localized enrichment at the critical interface region provides enhanced protection where electromigration damage is most severe, while maintaining the overall structure's integrity and extending device lifespan.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the compositional parameter by introducing manganese at specific concentrations (0.10 at% to 0.40 at%) into the seed material, which then segregates to form a manganese-rich layer at the interface. This parameter change transforms the uniform copper seed material into a compositional gradient structure that significantly improves both reliability and extends lifespan beyond the conventional barrier layer limitation.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If copper interconnect is used for low electrical resistance and high speed transmission, then the electrical performance is improved, but copper is prone to electromigration causing device malfunction

Engineering Contradiction:

Improveelectrical performanceVSAvoidelectromigration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces manganese as an intermediary element that segregates to the interface between the copper seed material and the barrier layer. This manganese-rich intermediate layer acts as a mediator that enhances the protective effect of the barrier layer against electromigration, while preserving the low resistance and high-speed transmission properties of the copper interconnect.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure by combining copper with manganese in the seed material, where the manganese segregates to form a distinct phase at the interface. This composite Cu-Mn structure leverages the excellent electrical conductivity of copper while the manganese component provides enhanced protection against electromigration through the formed manganese-rich layer.

Inventive Principle:

Principle #40Composite materials

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 significantly increases the semiconductor structure's lifespan, with a five-fold improvement under deteriorating conditions, by forming a manganese-rich layer that repairs defects and enhances the interface between the conductive material and the barrier layer.

Implementation Method 1

moving at least some of the manganese of the first seed material to a location proximate an interface between the first seed material and the first barrier layer

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

heating the first seed material to a temperature in a range of from 400° C. to 460° C. in a hydrogen atmosphere

Methodology Applied

Scientific EffectAnnealing: Annealing

Implementation Method 3

forming a first manganese-rich layer including manganese, manganese oxide or a combination thereof at the location

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS11562961B2Method of manufacturing semiconductor structure and semiconductor structure

Publication Date: 2023.01.24 NAN YA TECH

AI summary

A method of manufacturing a semiconductor structure includes: forming a first opening in a first dielectric material; forming a first barrier layer in the first opening; forming a first seed material including copper and manganese on the first barrier layer, in which the manganese in the first seed material is in a range of from 0.10 at % to 0.40 at %; forming a first conductive material on the first seed material; and moving at least some of the manganese of the first seed material to a location proximate an interface between the first seed material and the first barrier layer. Another method of manufacturing a semiconductor structure and a semiconductor structure are also provided.