How Machine Vision Applications in Semiconductor Manufacturing Boost Quality Control

Silicon wafers, which form the foundation of ICs, need to be manufactured and placed on top of each other in layers. Every single layer must align precisely. The orientation of a wafer notch, the tiny cut intentionally made on the edge of a silicon wafer for alignment purposes, is then checked. Using traditional inspection systems is slow and bulky, especially when it comes to accurately detecting a notch in transparent wafers.

KEYENCE vision systems with built-in AI help improve silicon wafer alignment due to the advanced and proprietary functions they feature. The AI capability is a deep learning tool that trains on a large data set of images to accurately recognize dots on even transparent wafers.

Catching defects early during production helps improve the production line yield rate per wafer by minimizing manual inspection and rework. Because wafers are stacked, each layer must be inspected before being deposited on the other to identify defects.

Without accurate inspection systems, classifying real defects from allowable cosmetic flaws becomes challenging, leading to rework and waste. Accurate defect detection and cost savings are other reasons to use machine vision in semiconductor quality control efforts.

Wafers, wafer carriers, dies, lead frames, integrated circuits, and other semiconductor components can be counterfeited. These components carry alphanumeric characters (for tracking and a human-readable format) and identification codes (for identification and a machine-readable format). Instead of using conventional methods to read codes and characters, vision systems make decoding easy and error-free even when codes are damaged or are difficult to read.

The complexity of the manufacturing process makes achieving a high yield, i.e., more good chips per wafer produced, challenging. Fortunately, accurate defect detection helps identify and eliminate defective wafers, helping maximize the percentage of good chips. Machine vision systems can improve yield rates by 3-5% through early detection of process drift and pattern defects that might otherwise go unnoticed until electrical testing.

Chemicals and foreign materials can contaminate wafers during production. Even the tiniest of particles can cause defects, leading to malfunctions of produced circuits. Advanced semiconductor processes now work at the 5 nm scale and below, where even particles smaller than 0.1 microns can cause defects. Vision system inspection can detect these invisible contaminants by analyzing light refraction patterns that reveal surface anomalies undetectable to the human eye.

Accurate temperature must be maintained to achieve consistency in the production of every part that goes into integrated circuits. Temperature variations as small as ±0.5°C can cause dimensional changes that affect lithography precision and chemical reaction rates. Modern fabrication facilities integrate real-time environmental monitoring with industrial vision systems. These allow automated compensation for micro-variations in conditions that would otherwise impact quality.

Using the wrong inspection systems can make wafer inspection difficult. The inspection system used must identify cracks, contamination, and scratches while making allowance for cosmetic flaws. The latest wafer vision system inspection technologies combine bright-field, dark-field, and phase contrast imaging to achieve defect sensitivity while maintaining throughput.

Using vision products that can perform inline 3D inspection provides significant benefits to the production of wafers, chips, and PCBs. By identifying defects early in the production process, these vision systems can reduce scrap rates and improve yields. 3D machine vision is also used in semiconductor manufacturing to improve defect detection. 3D vision systems create three-dimensional data, including depth profiles, which help uncover voids, undercuts, and delamination.

Line scan technology is also used in semiconductor production. These cameras are especially useful because they can perform accurate inspection of defects and contamination even on uneven surfaces. These specialized cameras deliver exceptionally high-resolution imaging, enabling accurate inspection of defects. By capturing data one line at a time as products move through production, line scan systems can detect microscopic flaws while maintaining throughput requirements.

Vision system inspection can check for wafer alignment, detect a wide range of defects, and enable accurate identification and tracing of wafers and chips. Modern AI-powered industrial vision systems leverage deep learning algorithms to distinguish between actual defects and acceptable variations, drastically reducing false positives. These intelligent systems continue improving over time as they process more image data, leading to increasingly accurate inspections without requiring explicit reprogramming.

A KEYENCE vision system for manufacturing delivers unprecedented inspection speeds without compromising accuracy, with specialized hardware capable of processing up to 64-megapixel images in milliseconds. The systems can capture entire PCBs in a single shot while simultaneously performing multiple inspection tasks, including component presence verification, dimensional measurement, and surface defect detection. This high-throughput capability allows semiconductor manufacturers to maintain production speeds while achieving 100% inspection coverage.

KEYENCE vision systems drastically cut labor expenses and human error by automating inspection procedures that previously needed manual intervention. Consistent quality is guaranteed throughout production runs of any length of time because of the system's capacity to function constantly without becoming tired or losing focus. Additionally, integrated reporting tools provide real-time production metrics that help identify bottlenecks and optimization opportunities throughout the manufacturing process.

KEYENCE vision systems establish complete component traceability through robust code reading capabilities that function even with partially damaged or low-contrast markings. A thorough audit trail is produced for regulatory compliance and process enhancement by automatically recording the timestamp data for each inspection result. Tracking pinpoints the exact time and location of production process flaws, enabling manufacturers to promptly isolate and resolve quality concerns.

KEYENCE AI vision systems for the semiconductor and electronics manufacturing industry help enhance operations. Our AI-powered vision system uses deep learning techniques to improve defect detection accuracy, read codes for traceability, and alignment checking. It can train on extensive image data to learn what is classified as defects and what is permissible as cosmetic flaws.

Our vision systems also enable high-speed and accurate inspections of various semiconductor components. A 64-megapixel camera can capture the entire PCB in one image shot, enabling simultaneous semiconductor inspections such as product measurement and differentiation.

To learn more about how our AI-powered vision can bring benefits to semiconductor manufacturing, contact us today.