Laser Dicing Modified Portions Interval Control

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Solution Overview

Problem

Laser dicing technology often results in meandering cleavage lines in semiconductor wafers, leading to potential cracks in device regions during grinding, and increasing the number of modified layers can cause film peeling or chipping due to distortion and vibration.

Innovation Solution

A method involving laser irradiation to create modified portions at varying intervals along the dicing region, with different depths and arrangements to control cleavage straightness and prevent film peeling or chipping, by adjusting the intervals and number of modified layers based on specific areas of the semiconductor chip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the number of modified layers is increased to ensure straightness of cleavage, then cleavage straightness is improved, but film peeling or chipping occurs due to distortion or vibration

Engineering Contradiction:

Improvecleavage straightnessVSAvoidfilm integrity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies different intervals between modified portions in different regions: a first interval in a first part of the division region and a second interval (smaller than the first) in a second part of the division region. This local differentiation allows the cleavage to remain straight while reducing the number of modified layers overall, thereby preventing film peeling and chipping.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If laser modification is performed to enable wafer splitting, then division capability is improved, but meandering of division lines occurs leading to cracks in device regions

Engineering Contradiction:

Improvewafer division capabilityVSAvoiddivision line straightness

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent segments the division region into multiple modified portions arranged in the direction along the division region. These modified portions are distributed throughout the thickness of the semiconductor wafer and serve as initiation points for cleavage, enabling controlled wafer division while maintaining straight division lines.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extends the modification from a single surface into the thickness dimension of the wafer by creating multiple modified portions at different depths. This three-dimensional arrangement of modified portions ensures straight cleavage propagation through the wafer thickness while preventing meandering of the division line.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Volume of moving object

If grinding process is applied to thin the semiconductor wafer, then wafer thickness is reduced, but meandering of division line increases causing cracks to reach device region

Engineering Contradiction:

Improvewafer thicknessVSAvoiddivision line straightness

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent performs laser modification to create multiple modified portions within the wafer thickness before the grinding process. These pre-established modification points serve as guides for cleavage propagation, ensuring that even after thinning through grinding, the division line remains straight and does not meander into device regions.

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

Improves the straightness of cleavage while preventing film peeling or chipping during the grinding process, maintaining wafer strength and reducing meandering of division lines, thereby enhancing the manufacturing process for semiconductor devices.

Implementation Method 1

irradiating a division region of a semiconductor wafer with laser to form a plurality of modified portions arranged in a direction along the division region

Methodology Applied

Scientific EffectLaser irradiation: Laser

Implementation Method 2

irradiating a division region of a semiconductor wafer with laser to form a plurality of modified portions

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

splitting the semiconductor wafer into a plurality of semiconductor chips using a groove generated from the plurality of modified portions

Methodology Applied

Scientific EffectCleavage: Fracture Mechanics

Data Source

PatentUS10892191B2Method of manufacturing a semiconductor device

Publication Date: 2021.01.12 KIOXIA CORP

AI summary

A method of manufacturing a semiconductor device, includes irradiating a division region of a semiconductor wafer with laser to form a plurality of modified portions arranged in a direction along the division region in the semiconductor wafer, and splitting the semiconductor wafer into a plurality of semiconductor chips using a groove generated from the plurality of modified portions in the semiconductor wafer. The plurality of modified portions is at a first interval in a first part of the division region and at a second interval smaller than the first interval in a second part of the division region.