Stealth Laser Wafer Edge Trimming With IR Alignment

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Solution Overview

Problem

The existing wafer edge trimming processes face challenges in precision and accuracy, leading to potential damage to the wafers and peeling issues during further processing steps.

Innovation Solution

The proposed solution involves using an infrared (IR) alignment process, a stealth laser apparatus to form a stealth damage (SD) region, and a blade trimming process to remove the outer region of the second wafer, thereby improving alignment accuracy and minimizing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional blade trimming is used to remove the outer region of the wafer, then the trimming process can be completed, but the abrasive surface of the blade may damage the wafer surfaces and cause peeling

Engineering Contradiction:

Improvewafer edge trimming processVSAvoidwafer damage and peeling

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The stealth laser forms a damage region within the wafer at a predetermined distance from the outer perimeter before blade trimming. This preliminary action creates a controlled weakness zone that guides the blade cutting path, allowing the blade to remove the outer region without directly contacting and damaging the critical inner wafer surfaces.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The stealth laser creates an intermediary damage region that acts as a mediator between the blade and the wafer's critical surfaces. This damage region serves as a buffer zone that absorbs the mechanical stress and abrasive contact, protecting the inner wafer regions from direct blade damage while still enabling effective trimming.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the blade directly contacts the wafer surface for trimming, then material removal is efficient, but precision and accuracy are compromised leading to potential damage

Engineering Contradiction:

Improvematerial removal efficiencyVSAvoidalignment accuracy and trimming precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The stealth laser pre-forms a damage region at a precisely controlled distance from the wafer's outer perimeter before blade contact. This preliminary positioning establishes an accurate reference zone that guides the blade along the correct cutting path, ensuring both precision in the trimming location and efficiency in material removal without direct blade-wafer surface contact.

Inventive Principle:

Principle #10Preliminary action

3Stability of the object's composition

If the wafer outer region is not trimmed, then the wafer structure remains intact, but peeling issues occur during further processing steps

Engineering Contradiction:

Improvewafer structural integrityVSAvoidpeeling resistance during processing

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The stealth laser creates a segmented damage region within the wafer that separates the outer trimmable region from the inner critical region. This segmentation allows the outer region to be removed while maintaining the structural integrity of the inner region, preventing peeling during subsequent processing steps by eliminating the problematic outer perimeter.

Inventive Principle:

Principle #1Segmentation

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 enhances the precision and accuracy of wafer edge trimming, reduces damage to the wafers, and mitigates peeling issues, resulting in smoother and defect-free outer edges of the second wafer.

Implementation Method 1

an infrared camera is used to locate alignment marks on the first wafer

Methodology Applied

Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

a stealth laser apparatus is used to form a damage region within the second wafer that separates an outer region of the second wafer from an inner region of the second wafer

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS20250079150A1Integrated stealth laser for wafer edge trimming process

Publication Date: 2025.03.06 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

In some embodiments, the present disclosure relates to a method. The method includes identifying an alignment mark within a substrate using an infrared camera. A stealth laser apparatus is aligned with respect to the substrate using the alignment mark. The alignment mark was used to perform a patterning process on the substrate prior to alignment of the stealth laser apparatus. The laser apparatus is operated to form a damage region within the substrate. The damage region separates an inner region of the substrate from an outer region of the substrate structure. A force is applied to the substrate to remove at least a part of the outer region of the substrate.