Semiconductor Die Separation via Segmented Trench Structures

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Solution Overview

Problem

The challenge in semiconductor device manufacturing lies in efficiently separating die areas on a wafer while preserving wafer-circuitry, which often includes metal elements, as not all dicing methods can handle these structures effectively, leading to loss of valuable circuitry during the separation process.

Innovation Solution

A method involving a wafer with die areas separated by trenches and a ridge on one face, and an additional trench on the opposite face, facilitates dicing while allowing for the preservation and potential reuse of wafer-circuitry, including metal structures, by using techniques like dry etching and plasma etching to form precise trench structures that aid in separation without damaging the circuitry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional dicing methods (sawing, breaking, etching) are used to separate die areas, then the separation efficiency is improved, but the wafer-circuitry with metal elements is damaged or lost

Engineering Contradiction:

Improvedicing separation efficiencyVSAvoidwafer-circuitry loss

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The scribe line is segmented into multiple portions (first scribe line portion, second scribe line portion, third scribe line portion) with different structures. The first portion contains the wafer-circuitry and is preserved, while the second and third portions are removed to create separation. This segmentation allows selective preservation of valuable circuitry while achieving effective die separation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The method extracts and removes only the necessary portions (second and third scribe line portions) while leaving the wafer-circuitry-containing portion intact. This selective extraction enables separation of die areas without sacrificing the valuable metal elements and circuitry structures.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If wafer-circuitry is allocated in dedicated portions (drop-in chips) to preserve it, then the circuitry is protected, but the yield is reduced as these portions cannot be used for semiconductor devices

Engineering Contradiction:

Improvewafer-circuitry preservationVSAvoidsemiconductor device yield

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The first scribe line portion serves multiple functions: it contains and protects the wafer-circuitry while also serving as part of the separation structure between die areas. This multi-functional design eliminates the need for dedicated non-productive drop-in chip areas, as the circuitry-containing region itself becomes part of the functional separation structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The solution moves the wafer-circuitry from dedicated lateral areas (drop-in chips) into the vertical dimension by embedding it within the scribe line structure itself. The circuitry is positioned in the first scribe line portion that remains after dicing, utilizing the separation structure's volume rather than requiring separate dedicated regions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If all scribe line material is removed to separate dice, then complete separation is achieved, but the valuable metal elements and circuitry are lost

Engineering Contradiction:

Improvedice separation completenessVSAvoidmetal elements and circuitry loss

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

Different portions of the scribe line are treated differently: the first scribe line portion is preserved with its metal elements and circuitry intact, while the second and third portions are completely removed. This localized differential treatment achieves complete die separation while conserving valuable materials in the preserved portion.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The method discards only the non-essential portions (second and third scribe line portions) while recovering and preserving the valuable first scribe line portion containing metal elements and circuitry. The preserved portion can be reused or repurposed, turning potential waste into a recoverable resource.

Inventive Principle:

Principle #34Discarding and recovering

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 enables effective separation of die areas while minimizing the loss of wafer-circuitry, allowing for the reuse of valuable test circuitry and structural elements, thus improving the yield and efficiency of semiconductor device production.

Implementation Method 1

forming a first trench and a second trench spaced apart from one another by a ridge

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS10510626B2Method for use in manufacturing a semiconductor device die

Publication Date: 2019.12.17 INFINEON TECHNOLOGIES AG

AI summary

In one embodiment, a wafer includes a number of die areas each including a semiconductor device and dedicated to become a separate die. The die areas are disposed on a first face of the wafer and wherein adjacent die areas are distanced from one another. A first trench and a second trench are formed on the first face between adjacent die areas. The first trench and the second trench are spaced apart from one another by a ridge. A third trench is disposed above the ridge on a second face of the wafer.