Inspection and characterization have three main roles.

・Preventing defective products from escaping

・Improving yield

・Assuring reliability

It is not mere product checking; it is also a data source directly linked to process improvement.

The areas covered in Chapter 7 are as follows.

Visual Inspection

・Pattern defects

・Particles

・Scratches

Electrical Characteristic Testing

・Wafer probing

・Final test

In-Line Metrology

・Film thickness

・CD

・Overlay

Defect Inspection

・Optical

・Electron beam

Failure Analysis (FA)

・SEM

・FIB

・TEM

Reliability Evaluation

・TDDB

・EM

・BTI

Yield Data Analysis

・SPC

・AI analysis

Inspection is not a single process but a cross-functional capability that runs through the entire factory.

There are three reasons.

① Features are extremely small

・Defects of a few nm

・Atomic-level structures

② Non-destructive requirements

・Seeing without destroying

・Seeing inside

③ Supporting high-speed volume production

・Millions of chips every day

・Constraints on inspection time

In other words: precision × speed × non-destructiveness

All three must be achieved at once.

The axes of evolution are clear.

・Optical → electron beam

・2D → 3D

・Sampling → 100% inspection

・Human judgment → AI

AI adoption in particular is progressing rapidly.

What has changed with the introduction of AI:

・Automated defect classification

・Fewer false detections

・Faster inspection

・Detection of unknown defects

Conventional rule-based approaches have reached their limits.

Going forward, inspection design that assumes AI will be essential.

Inspection does not exist in isolation.

・Design (DFM)

・Processes

・Equipment

・Materials

Inspection data is fed back, improving manufacturing precision.

Inspection is also a cost.

・Expensive equipment

・Inspection time

・Lower throughput

Excessive inspection squeezes profits.

For this reason, optimal inspection design is important.

In the early stages of volume production, dependence on inspection is high.

・Many unknown defects

・Low process stability

Inspection data accelerates process improvement.

It becomes the trigger for yield improvement.

Difficulty rises with scaling.

・Stochastic defects

・EUV mask defects

・Line edge roughness

・Internal 3D defects

It is a battle against the limits of inspection.

At the leading edge, the back-end is the main battleground.

・Bump connections

・RDL disconnections

・TSV defects

・Delamination

Package inspection = performance assurance.

The required skills are diverse.

・Understanding of devices

・Process knowledge

・Statistical analysis

・Understanding of equipment

・Materials knowledge

Not merely someone who measures, but a well-rounded engineer.

In the factory of the future, inspection becomes real-time.

・In-line 100% inspection

・AI anomaly detection

・Immediate process correction

Inspection is integrated into the control system.

Directions of evolution:

・Atomic-level inspection

・Evaluation of quantum devices

・Optical I/O inspection

・Evaluation of liquid-cooled packages

・Autonomous inspection robots

It evolves at the same pace as manufacturing.

・Inspection is the foundation of quality assurance

・It encompasses visual, electrical, and reliability evaluation

・Difficulty is rising sharply with scaling

・AI inspection is becoming the main player

・Inspection data improves yield

・In smart fabs, it is integrated with the control system

1.Why is inspection technology said to be “manufacturing technology itself”?

2.In what ways is AI inspection superior to conventional methods?

3.What is the main reason inspection becomes more difficult at advanced nodes?

4.Why is the balance between inspection cost and quality important?

 

Column Supervisor: Koji Kakumoto (President, OTIS Co., Ltd.)

After studying abroad and working in planning and development at a trading company, he joined OTIS Co., Ltd. in 2011. While primarily working in the Corporate Planning Department, he has also served concurrently in manufacturing and technical divisions, and since 2018 has served as President, working to drive business growth and strengthen the organization.

 

This article is a general technical explanation intended for educational purposes and does not refer to any specific company, product, or technology.