WiMi Hologram Cloud Inc., a global Hologram Augmented Reality (“AR”) Technology provider, today announced that an innovative detection technique based on digital holography has been developed to meet the needs of semiconductor wafer defect detection. The technique utilizes digital holography to record the amplitude and phase of the wavefront from the target object directly to the individual images acquired by the CCD camera, and can effectively detect defects on wafers as small as a few nanometers by resolving the phase difference of the height difference.
Digital holography is a high-resolution imaging technique based on optical principles that records and analyzes wavefront information about a target object. By utilizing deep ultraviolet laser illumination and phase difference analysis, the technique is able to accurately detect defects as small as a few nanometers on structures with high aspect ratios. Compared to traditional defect detection methods, digital holography has the advantages of higher sensitivity, better resolution, and non-destructive testing. Defect detection on semiconductor wafers has always been an integral part of the semiconductor manufacturing process. As the size of semiconductor devices continues to shrink and process complexity, traditional defect detection methods are facing challenges. To address this issue, WiMi’s R&D team has successfully introduced digital holography into the defect inspection of semiconductor wafers through their tireless efforts.
Digital holography utilizes deep-ultraviolet laser illumination to record the amplitude and phase information of the wavefront of the target object. By dividing the laser beam into reference light and object light and irradiating them onto the CCD camera and the object to be measured respectively, the interference patterns of the reference light and object light are obtained. Then, the amplitude and phase information of the object light can be recovered from the interference pattern by a mathematical reconstruction algorithm. The phase information can accurately reflect the surface topography of the target object.
WiMi’s successful development of semiconductor wafer defect detection technology through the use of digital holography will bring many benefits to the semiconductor manufacturing industry. First, digital holography can improve manufacturing yields and reduce the production and waste of defective products. Its high sensitivity and resolution make defect detection of high aspect ratio features more accurate and reliable, helping to identify and solve production problems early.
Second, digital holography provides phase information of defects, allowing users to visualize and analyze the morphology, size and topology of defects. This is important for understanding the defect generation mechanism and optimizing the manufacturing process. In addition, the technology generates a 3D image of the wafer surface, further providing visualization and in-depth analysis of defects.
WiMi’s digital holography technology has achieved remarkable results in several experiments and tests. Digital holography has shown unique advantages over other wafer inspection techniques in detecting defects in high aspect ratio structures. The technique has been successfully applied to several benchmark wafers for defect detection and compared with other conventional methods. The experimental results show that digital holography has excellent performance in detecting defects in high aspect ratio features. In particular, for defects with height differences as small as a few nanometers, such as incorrectly etched contacts, digital holography is able to accurately capture them and provide high-quality phase and amplitude images. Digital holography offers the following advantages in semiconductor wafer defect detection.
High sensitivity and resolution: Digital holography is capable of detecting defects as small as a few nanometers, and has high sensitivity and resolution for detecting defects in high aspect ratio structures.
Non-destructive testing: Digital holography is a non-contact inspection method that does not physically damage the wafer sample and maintains the integrity and repeatability of the sample.
Defect visualization and topology analysis: Digital holography provides phase information of defects, allowing users to visualize and analyze the morphology, size and topology of defects. This is important for understanding the defect generation mechanism and optimizing the manufacturing process.
Automation and efficiency: Digital holography can be combined with image processing and machine learning algorithms to automate defect detection and classification. By analyzing large amounts of data, defects can be identified and located quickly and accurately, improving productivity and manufacturing yields.
In comparison to other techniques, digital holography offers significant advantages in the detection of defects in high aspect ratio features, such as incorrectly etched contacts. Digital holography is able to accurately capture these defects, thus improving defect detection for high aspect ratio features.
In addition to superior detection capabilities, digital holography offers the benefits of automation and efficiency. By combining it with image processing and machine learning algorithms, the technology enables automated defect detection and classification. By analyzing large amounts of data, defects can be quickly and accurately identified and located, resulting in improved productivity and manufacturing yields.
Digital holography technology has a broad application prospect in the field of semiconductor wafer defect detection. With the continuous development of semiconductor processes and the increased demand for nanoscale manufacturing, the demand for high-resolution, high-sensitivity defect detection technology is increasing. Digital holography, as a non-contact, high-resolution imaging technology, is expected to become an important tool in semiconductor manufacturing and promote the progress of semiconductor manufacturing.
