Wafer inspection

This process involves inspection of foreign matters and defects on a wafer, and pattern measurement.

Inspection for foreign matters and defects
Electron beam detection
Control of the resistance value
Common process steps across semiconductor manufacturing

Wafer inspection in semiconductor manufacturing, involves the meticulous examination of semiconductor wafers to identify and address defects or irregularities. This process is essential for ensuring the quality and reliability of the final semiconductor devices. Various inspection techniques, including optical and electron microscopy, are employed to scrutinize the wafer's surface for imperfections such as particles, scratches, or pattern deviations.

Automated inspection systems play a significant role in speeding up the inspection process and enhancing accuracy. These systems use advanced algorithms and image processing techniques to analyze large quantities of wafers quickly. Wafer inspection is typically carried out at multiple stages throughout the semiconductor fabrication process, including after key steps such as lithography, etching, and deposition. Early detection and resolution of defects during wafer inspection contribute to the optimization of semiconductor manufacturing, ensuring the production of high-quality and reliable electronic components.

Inspection for foreign matters and defects

In wafer inspection, a critical focus is placed on identifying and addressing foreign materials and defects that have the potential to cause failures in semiconductor devices. The inspection process is nondestructive and noncontact, utilizing advanced techniques to detect minute foreign matters and microdefects on the wafer surface. This approach is particularly vital as semiconductor devices follow the trend of becoming smaller, finer, and more highly integrated.

As the demand for increased device precision grows, noncontact inspection methods have become essential. These techniques involve the use of advanced optical and imaging technologies, allowing for the detection of microscopic imperfections without physical contact with the wafer. By adopting nondestructive inspection strategies, semiconductor manufacturers can maintain the integrity of the wafers while ensuring the early identification and resolution of foreign materials and defects. This proactive approach is crucial for optimizing the manufacturing process, enhancing the yield, and producing semiconductor devices with superior quality and reliability.

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Microfocus X-ray sources

These are microfocus X-ray sources for X-ray nondestructive inspection. The Micro-focus enables the acquisition of high-definition X-ray images even at high geometric magnification.

X-ray I.I. camera unit & X-ray I.I.

These 2D X-ray cameras are used for nondestructive X ray inspection. These cameras have a magnification function, enabling the acquisition of high-resolution, high-contrast X-ray images at high speeds.

Photomultiplier tubes

Photomultiplier tubes are widely used in semiconductor wafer inspection systems. In wafer inspection, the wafer is scanned by a laser beam, and the scattered light caused by dirt or defects is detected by a photomultiplier tube.

The following photomultiplier tubes are recommended for their high quantum efficiency, good uniformity and low spike noise.

Laser-Driven Light Sources (LDLS)

These are the world's only light sources that use a method of maintaining emission by generating plasma with a focused laser beam between discharge electrodes in a bulb filled with xenon gas. Compared to conventional xenon lamps, these light sources provide higher bright light in the ultraviolet region and have features such as long life and minute emission points.

X-ray TDI cameras

These 1D X-ray cameras are used for nondestructive X-ray inspection. These cameras image the inside of an object being transported with X-rays. High-speed imaging is possible, and it can also be used for total inspection.

TDI cameras

These cameras use “time delay integration (TDI)” — a special readout method for CCDs. The combination of high speed and high sensitivity enables clear imaging by integrating images according to the movement of the inspected object being transported.

APDs

These photodiodes are high-speed and highly sensitive, and the photocurrent is multiplied by applying a reverse voltage. High S/N is obtained, making it suitable for faint light detection.

Electron beam detection

In wafer inspection, electron beam detection is a sophisticated technique employed to scrutinize semiconductor wafers with high precision. This method utilizes an electron beam for detection, a process achieved by combining a scintillator and a photodetector. The synergy of these components allows for the conversion of the electron beam interactions into detectable signals. One notable advantage of using electron beams is the equipment's higher resolution, enabling the identification of finer details and defects on the wafer surface.

The electron beam detection process involves the generation of electrons that interact with the wafer, producing signals that are then captured and analyzed. This method provides a level of resolution that is particularly beneficial as semiconductor devices continue to evolve, becoming smaller and more intricately designed. The use of electron beam detection in wafer inspection contributes to the advancement of semiconductor manufacturing by ensuring a thorough examination of the wafer for defects, ultimately enhancing the overall quality and reliability of the produced electronic components.

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Fast decay phosphors

These are highly sensitive detectors and devices that convert electrons into light. They are used for various defect inspections, endpoint monitors, and other applications. The combination with a photomultiplier tube and a high-speed phosphor enables even detection of faint electron beams that cannot be detected by a photodiode.

VUV Ionizer: Electrostatic charge removers

These static eliminators can be used in vacuum which has been previously difficult. Using high-energy vacuum ultraviolet rays achieves high static elimination performance.

APDs

These photodiodes are high-speed and highly sensitive, and the photocurrent is multiplied by applying a reverse voltage. High S/N is obtained, making it suitable for faint light detection.

Photodiodes for electron beam detection

These Si photodiodes are used for low-energy electron beam detection.

Control of the resistance value

In wafer inspection, the control of resistance values plays a pivotal role in optimizing product performance. This involves the precision trimming of circuit patterns or electronic components on a wafer or glass substrate. Laser ablation is a key technique employed for this purpose, allowing for the selective removal of material to achieve the desired resistance values for each chip.

The process of laser ablation involves cutting or trimming circuit patterns with a high-powered laser, enabling intricate adjustments to the resistance values of individual electronic components. This level of control is crucial for tailoring the performance of semiconductor devices, ensuring that each chip meets the specified requirements. By utilizing laser ablation in wafer inspection, manufacturers can enhance the precision and efficiency of resistance value control, contributing to the production of semiconductor devices with improved overall functionality and reliability.

Common process steps across semiconductor manufacturing

Electrostatic charge removal (ESD)

Explore Hamamatsu's meticulously engineered electrostatic charge removal solutions, designed to enhance reliability across various processes. Our technology efficiently removes charges that could potentially damage the wafer, ensuring high-quality processes.

Thickness measurement

Optimize precision in material analysis with Hamamatsu's solutions for thickness measurement. Explore our technologies designed for accurate and reliable thickness measurement across various materials and see how we are helping the industry with advanced measurement capabilities, ensuring superior quality and performance for your applications.

Wafer alignment

Elevate semiconductor manufacturing with Hamamatsu's solutions for wafer alignment. Our technologies are designed for accurate wafer positioning, enhancing efficiency and yield in semiconductor production. Discover how we are helping wafer alignment, delivering unparalleled reliability and performance for your semiconductor processing needs.