SPARC Wafer FactoryIntroduction: The semiconductor industry generally requires high efficiency and accuracy in wafer surface defect detection, capable of capturing effective defects and achieving real-time detection. Common surface inspection technologies can be divided into two categories: contact methods and non-contact methods. The contact method is represented by the needle contact method; the non-contact method can be divided into atomic force methods and optical methods. In specific applications, they can be categorized into imaging and non-imaging.

　　The needle contact method, as the name suggests, involves detecting the contact between the probe and the material being tested. It is one of the earlier surface inspection methods in the manufacturing industry. The shape and profile information of the measured surface are transmitted to the sensor through the probe, making the size and shape of the probe particularly important. According to the detection principle of the needle contact method, it is only possible to detect the true profile of the object being measured when the radius of the probe tip approaches 0. However, the finer the probe tip, the longer the probe, which increases the pressure on the measured surface, leading to wear on the probe and potential scratching of the surface of the object being measured. For coated surfaces and soft metals, contact detection can easily damage the surface of the sample and is generally not applicable.

　　In 1981, Binnig and Rohrer invented the Scanning Tunneling Microscope (STM). STM utilizes the quantum tunneling effect, with the probe tip and the surface of the object being measured as two poles. A very fine probe approaches the sample surface, and when the distance is very close, a tunneling junction is formed. By keeping the distance between the probe tip and the sample surface constant, the probe tip performs three-dimensional movements on the sample surface, transmitting the atomic heights sensed by the probe tip to a computer, which processes the data to obtain the surface morphology of the object being measured. Due to the limitations of using STM, Binnig and others developed the Atomic Force Microscope (AFM) based on STM. AFM detects the attractive or repulsive forces between the probe tip and the specimen, making it applicable to both conductive and non-conductive materials.

　　SPARC Wafer Factory indicates,Scanning Near-field Optical Microscopy (SNOM) uses the characteristics of the near-field light around the sample surface to detect its surface morphology. Its resolution can greatly surpass the resolution limit of conventional microscopes (λ/2).

　　Currently, the commonly used imaging inspection methods in the semiconductor industry mainly include Automated Optical Inspection, X-ray inspection, and Electron Beam Inspection. The Scanning Electron Microscope (SEM) is a tool invented in 1965 for studying microscopic objects. SEM uses an electron beam to scan the sample, causing secondary electron emission from the sample, which can produce magnified images of the sample surface. These images are magnified point by point in a certain order. The advantage of SEM lies in its extremely high resolution.

　　By combining X-ray non-destructive testing technology with digital image processing technology, high-resolution inspection of internal wiring of equipment can be achieved. Agilent has a high market share, with typical products including the 5DX system.

　　SPARC Wafer Factory indicates,Automated Optical Inspection (AOI) technology is a detection technology based on optical principles. It utilizes the movement of precision instrument platforms and image acquisition devices combined with digital image processing technology to detect defects on the surface of samples.Wafer, the advantage is faster detection. AOI equipment has developed rapidly in recent years in China, indicating significant market potential. AOI technology captures images through CCD or CMOS sensors, which are then converted to digital signals and transmitted to a computer, where they are compared with standard images after digital image processing.