As the cornerstone of modern electronic information industry, the semiconductor industry is constantly evolving towards nanometer and even sub nanometer level manufacturing processes, and the accuracy of each process directly determines the performance and yield of the final product. In this context,3D profilometerWith its high-precision and non-contact measurement capabilities, it has become the core equipment for surface morphology and size detection in the entire semiconductor manufacturing process. Among them, the confocal 3D profilometer, which integrates the principle of confocal optics and white light interference technology, is widely used in key areas such as wafer manufacturing, advanced packaging, and microelectromechanical systems due to its excellent performance, providing strong technical support for fine quality control in the semiconductor industry.
1、 Strict requirements for surface inspection in semiconductor manufacturing
The manufacturing of semiconductor chips involves hundreds of precision processes, from silicon wafer cutting, thin film deposition, photolithography exposure to etching, chemical mechanical polishing, and packaging testing, each step may introduce surface defects or dimensional deviations. For example, if the height deviation of bumps in wafer level packaging exceeds 1 μ m, it may cause the connection between the chip and the substrate to fail; The uneven thickness of the photoresist layer will directly affect the accuracy of the photoresist pattern, leading to chip scrap; If the surface roughness after chemical mechanical polishing does not meet the standard, it will affect the adhesion and uniformity of subsequent film deposition.
Traditional two-dimensional detection equipment can only obtain planar information and cannot fully characterize the morphological features of three-dimensional surfaces. However, 3D profilometers can achieve three-dimensional digital reconstruction of sample surfaces, accurately measure key parameters such as step height, surface roughness, defect size, stress distribution, etc., meeting the detection requirements of semiconductor manufacturing for nanometer level accuracy. With the mass production of advanced processes at 3nm and below, the semiconductor industry's precision requirements for detection equipment have further increased. Traditional detection methods can no longer meet production needs, and the importance of confocal 3D profilometers has become increasingly prominent.
2、 Core technological advantages of confocal 3D profilometer
The confocal 3D profilometer adopts a technical route combining white light interference and confocal imaging, which has significant technical advantages compared to traditional contact measurement equipment and single principle optical measurement equipment.
One is the ultra-high measurement accuracy. Taking the KLA Profilm3D confocal 3D profilometer from Nikon as an example, when using phase interference (PSI) technology, its vertical resolution can reach sub nanometer level (<1nm), RMS repeatability is as low as 0.1nm, and the step height accuracy reaches 0.7%, which can accurately capture nanoscale morphological changes on the surface of semiconductor devices. When using vertical interference scanning (WLI) technology, its measurement range can cover 50nm to 10mm, balancing the requirements of high precision and wide range.
Secondly, it has a large field of view and high compatibility. When equipped with a 10x objective lens, this type of device can achieve a field of view range of 2mm and support up to 4x optical zoom, which can meet measurement needs at different scales without frequent lens replacement; Equipped with a 100mm automatic XY sample table, it can automatically complete multi-point measurement and area scanning, greatly improving detection efficiency. The sample reflectivity is suitable for a range of 0.05% -100%, and can measure various materials from high reflectivity metal surfaces to low reflectivity transparent films.
Thirdly, the confocal 3D profilometer adopts a non-contact measurement method, which will not cause any damage to the tested sample, and is particularly suitable for the detection of sensitive materials such as photoresist, soft polymers, and biochips. The measurement process is simple and fast, completing a single measurement within seconds and outputting a complete parameter report including surface roughness, shape, and step height. It also supports multi image stitching function, which can achieve surface morphology analysis of large-area samples.
3、 The key application of 3D profilometer in the entire semiconductor process
3D profilometers play an irreplaceable role in multiple key stages of semiconductor manufacturing. During the wafer manufacturing stage, it can be used to measure the surface roughness, flatness, and defects of silicon wafers to ensure that the quality of the wafer substrate meets the subsequent process requirements; In the thin film deposition process, it is possible to accurately measure the thickness and uniformity of dielectric thin films such as silicon oxide and silicon nitride, as well as the morphological characteristics of the thin film surface.
In the photolithography and etching process, a 3D profilometer can be used to detect the thickness, contour, and edge morphology of the photoresist layer, as well as the depth and dimensional accuracy of the etched grooves and holes, in order to promptly detect process deviations and make adjustments. In the field of advanced packaging, 3D profilometer is the core equipment for detecting the height and coplanarity of convex points in wafer level packaging and flip chip packaging. It can quickly complete the three-dimensional measurement of thousands of convex points on the entire wafer, generate a uniform distribution map, and provide data support for packaging process optimization.
In addition, 3D profilometers can also be used for structural dimension measurement of microelectromechanical systems (MEMS) devices, surface quality inspection after chemical mechanical polishing, and pin flatness inspection after chip packaging in multiple scenarios. As a company that has been deeply involved in the field of precision measurement for more than ten years, Unicon Technology has provided customized detection solutions based on 3D profilometers to numerous semiconductor companies, helping customers effectively improve product yield and production efficiency.
4、 The underlying reason why confocal 3D profilometer has become a standard in the industry
The reason why confocal 3D profilometer can become a core equipment in the field of semiconductor detection is not only due to its excellent technical performance, but also due to its high cost-effectiveness and ease of use. Compared to other high-precision 3D measurement devices, confocal 3D profilometers achieve sub nanometer level measurement accuracy at relatively low costs, meeting the detection needs of the vast majority of semiconductor manufacturing processes and significantly reducing equipment investment costs for enterprises.
At the same time, this type of device is equipped with intuitive and easy-to-use operating software, with thousands of material databases built-in. Operators can easily use it after simple training, without the need for a strong background in optics and metrology. Its measurement data has good traceability and repeatability, meets the strict quality control standards of the semiconductor industry, and can provide reliable data support for the production process of enterprises.
With its rich industry experience and comprehensive service system, Unicon Technology can provide customers with full process support from equipment selection, installation and commissioning to after-sales maintenance, helping customers fully leverage the performance advantages of 3D profilometers and solve various precision measurement problems. With the continuous advancement of semiconductor manufacturing processes, the requirements for accuracy and efficiency of detection equipment are also constantly increasing. With its technological advantages and wide applicability, confocal 3D profilometers will undoubtedly occupy a more important position in the future semiconductor detection field.
