Wafer Inspection Line Sensor Foreign Matter Detection

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Solution Overview

Problem

The increasing scale integration of IC and LSI devices leads to reduced space between electrodes, making them susceptible to foreign matter deposition causing short circuits, and existing inspection methods using microscopes are inefficient, reducing productivity.

Innovation Solution

A wafer inspecting method and device utilizing a line sensor with multiple elements arranged in a line to scan the wafer surface along streets, determining foreign matter deposition near electrodes, and including alignment, displaying, and recording means to efficiently inspect and determine electrode integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the space between electrodes is reduced to increase scale integration, then device functionality is improved, but the risk of foreign matter deposition causing short circuits increases

Engineering Contradiction:

Improvescale integrationVSAvoidshort circuit risk

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent performs foreign matter detection inspection before dicing and electrode formation processes. By using a line sensor to scan the wafer surface and detect foreign matter deposits in advance, the system prevents foreign matter from causing short circuits between closely-spaced electrodes, thus maintaining reliability while enabling high scale integration

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If a microscope is used to check the wafer for deposited foreign matter, then detection accuracy is improved, but productivity is reduced due to inefficiency

Engineering Contradiction:

Improveforeign matter detection accuracyVSAvoidinspection efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the manual microscope inspection method with an automated line sensor-based optical inspection system. The line sensor scans the wafer surface automatically, capturing images of foreign matter deposits without requiring manual operation, thereby maintaining detection accuracy while dramatically improving inspection speed and productivity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses optical imaging to create a visual copy of the wafer surface, allowing foreign matter detection through image analysis rather than direct visual inspection with a microscope. This copying approach enables automated processing and maintains precision while improving efficiency

Inventive Principle:

Principle #26Copying

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

Enables efficient detection of foreign matter near electrodes, preventing short circuits and improving productivity by matching inspection speed with dicing processes, allowing for timely and accurate assessment of wafer quality.

Implementation Method 1

scanning the surface of the wafer along the streets by using a line sensor having a plurality of elements arranged in a line

Methodology Applied

Scientific EffectOptical scanning: Light

Data Source

PatentUS7675614B2Wafer inspecting method and device

Publication Date: 2010.03.09 DISCO CORP

AI summary

A wafer inspecting method including the steps of scanning the surface of a wafer along a street by using a line sensor having a plurality of elements arranged in a line, and determining a deposited condition of foreign matter on the surface of the wafer near electrodes formed on both sides of the street according to image information obtained by the above scanning step. By the use of the linear sensor, it is possible to efficiently determine whether or not the electrodes are good.