Compressive Nitride Passivation for Semiconductor Bonding Pad Protection

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Solution Overview

Problem

Conventional semiconductor devices face challenges in protecting bonding pads from acid corrosion and ensuring reliable electrical characteristics, particularly during pin hole tests, due to the use of tensile passivation layers that can crack and provide weak protection.

Innovation Solution

The implementation of a compressive nitride-based passivation layer with a refractive index of about 2.16 to 2.18, deposited using a radio frequency greater than 700 watts, which offers high ultraviolet transmittance and acid resistance, is used to protect the bonding pads and improve the reliability of semiconductor devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a tensile passivation layer is used to protect bonding pads, then the passivation layer provides basic protection, but it cracks under stress and fails to prevent acid corrosion

Engineering Contradiction:

Improveacid corrosion protectionVSAvoidpassivation layer integrity

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the stress state parameter of the passivation layer from tensile to compressive. The compressive stress prevents crack formation and propagation, allowing the passivation layer to maintain integrity during acid corrosion resistance and pin hole tests, thereby resolving the contradiction between protection capability and structural reliability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite passivation structure consisting of a compressive nitride-based layer combined with an oxide-based layer. This composite material approach provides both mechanical integrity (crack prevention) and chemical resistance (acid corrosion protection), simultaneously addressing both requirements

Inventive Principle:

Principle #40Composite materials

2Reliability

If conventional passivation layers are used, then manufacturing is simpler, but electrical characteristics are unreliable due to cracking

Engineering Contradiction:

Improveelectrical characteristicsVSAvoidpassivation layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies the stress parameter and material composition of the passivation layer to create a compressive nitride-based layer. This ensures reliable electrical characteristics by preventing cracks that would compromise bonding pad integrity, while the controlled structural addition maintains manufacturing feasibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies different material properties to different regions of the passivation structure. The compressive nitride-based layer provides mechanical strength and stress control, while the oxide-based layer provides electrical insulation and corrosion resistance, achieving reliable electrical characteristics through localized material optimization

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If a passivation layer with high acid resistance is used, then corrosion protection is improved, but ultraviolet transmittance may be reduced affecting data erasure

Engineering Contradiction:

Improveacid corrosion resistanceVSAvoidultraviolet transmittance

Core Design Contradiction:

Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent uses a composite passivation structure where the nitride-based layer (with high acid resistance) is combined with an oxide-based layer (with good UV transmittance). This composite approach allows the device to simultaneously achieve high corrosion protection and maintain sufficient ultraviolet transmittance for data erasure operations

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent assigns different functional properties to different layers: the nitride-based layer provides acid corrosion resistance, while the oxide-based layer provides ultraviolet transmittance. This local differentiation of material functions resolves the contradiction between corrosion protection and UV accessibility

Inventive Principle:

Principle #3Local quality

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 compressive nitride-based passivation layer effectively prevents acid corrosion, enhances electrical characteristics, and allows for efficient data erasure using ultraviolet rays, thereby improving the reliability and functionality of semiconductor devices, including those requiring one-time-programmable functions.

Implementation Method 1

the passivation layer includes a nitride-based layer with a refractive index of about 2.16 to 2.18... offers high ultraviolet transmittance and acid resistance

Methodology Applied

Scientific EffectAcid resistance:

Implementation Method 2

offers high ultraviolet transmittance... allows for efficient data erasure using ultraviolet rays

Methodology Applied

Scientific EffectUltraviolet transmittance:

Implementation Method 3

Methodology Applied

Scientific EffectCompressive stress:

Data Source

PatentUS9589969B1Semiconductor device and manufacturing method of the same

Publication Date: 2017.03.07 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Semiconductor devices and manufacturing methods of the same are disclosed. The semiconductor device includes a die, a conductive structure, a bonding pad and a passivation layer. The conductive structure is over and electrically connected to the die. The bonding pad is over and electrically connected to the conductive structure. The passivation layer is over the bonding pad, wherein the passivation layer includes a nitride-based layer with a refractive index of about 2.16 to 2.18.