Semiconductor Chip Division Chipping Prevention

Solution Overview

Problem

The existing semiconductor device chip manufacturing method using stealth dicing before grinding (SDBG) often results in chipping damage at the corners of semiconductor device chips, particularly in 45-degree product wafers with division lines inclined 45 degrees with respect to the <100> direction, due to crack extension and corner contact between adjacent chips.

Innovation Solution

A semiconductor device chip manufacturing method that includes forming a chipping prevention layer at the intersections of crossing division lines on the wafer, applying a protective tape, and using a laser beam to create a modified layer inside the wafer for division, which prevents chipping by reducing friction between adjacent chips during grinding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a laser beam is applied to the back side of the wafer to form a modified layer inside the wafer for division, then the wafer can be divided into individual semiconductor device chips, but cracks are generated between adjacent chips causing corner contact and chipping damage

Engineering Contradiction:

Improvewafer division efficiencyVSAvoidchipping damage at chip corners

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The chipping prevention layer is formed at the intersections of division lines on the front side of the wafer before the laser beam processing and grinding steps are performed on the back side. This preliminary formation of protective layers at critical locations prevents chipping damage before the harmful effects can occur during the division process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The chipping prevention layer acts as an intermediary protective structure between adjacent semiconductor device chips at their corner intersections. This intermediate layer absorbs or distributes the mechanical stress and friction that would otherwise cause direct corner-to-corner contact and chipping damage during the wafer division process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If grinding pressure is applied to divide the wafer into individual chips, then the wafer is successfully divided, but the corners of adjacent chips come into point contact causing damage

Engineering Contradiction:

Improvewafer division processVSAvoidchip corner integrity

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The chipping prevention layer is formed at the intersections of division lines on the front side of the wafer before the laser beam processing and grinding steps are performed on the back side. This preliminary formation of protective layers at critical locations prevents chipping damage before the harmful effects can occur during the division process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The chipping prevention layer acts as an intermediary protective structure between adjacent semiconductor device chips at their corner intersections. This intermediate layer absorbs or distributes the mechanical stress and friction that would otherwise cause direct corner-to-corner contact and chipping damage during the wafer division process.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method effectively prevents chipping at the corners of semiconductor device chips by forming a chipping prevention layer at the intersections of division lines, ensuring that even when adjacent chips contact each other, the risk of damage is minimized, and the chips are successfully divided without extensive cracking.

Implementation Method 1

applying a laser beam having a transmission wavelength to the wafer to the back side thereof along each division line in the condition where the focal point of the laser beam is set inside the wafer, thereby forming a modified layer due to multiphoton absorption inside the wafer

Methodology Applied

Scientific EffectMultiphoton absorption: Absorption (EM radiation)

Implementation Method 2

grinding the back side of the wafer to thereby reduce the thickness of the wafer and also divide the wafer into the individual semiconductor device chips

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS9935008B2Semiconductor device chip manufacturing method

Publication Date: 2018.04.03 DISCO CORP

AI summary

Disclosed herein is a semiconductor device chip manufacturing method including a chipping prevention layer forming step of forming a chipping prevention layer at each intersection of a plurality of crossing division lines formed on the front side of a wafer, a modified layer forming step of applying a laser beam having a transmission wavelength to the wafer to the back side thereof along each division line in the condition where the focal point of the laser beam is set inside the wafer, thereby forming a modified layer inside the wafer along each division line, and a dividing step of grinding the back side of the wafer after performing the modified layer forming step, thereby reducing the thickness of the wafer and also dividing the wafer into individual semiconductor device chips along each division line where the modified layer is formed as a break start point.