In today's rapid development of science and technology, the manufacturing process of semiconductors, as the core components of modern electronic equipment, is undoubtedly one of the most complex and sophisticated processes in the scientific and technological world. From the initial silicon ore refining to the advent of the final chip, semiconductor manufacturing involves several key steps, among which wafer preparation, oxidation process, photolithography, doping process and thin film process are known as the five cornerstones of semiconductor manufacturing. In this article, we'll take a deep dive into these processes and reveal how they are collectively shaping the blueprint for the future of technology.
Wafer Preparation: The Beginning of the Semiconductor World
It all starts with the wafer, which is a seemingly ordinary, round wafer, but it is the core foundation of semiconductor manufacturing. The wafer preparation process includes the refining and purification of silicon, the growth of monocrystalline silicon, and the shaping of wafers. In this process, high-purity polysilicon undergoes a series of complex chemical reactions and physical treatments to transform into monocrystalline silicon wafers up to 12 inches in diameter. These wafers act as canvases waiting for the process to draw complex circuit patterns on them.
Oxidation process: construction of an insulating barrier
The formation of a thin layer of silicon dioxide on the surface of the wafer is the main task of the oxidation process. This oxide layer not only provides excellent insulating properties, but also protects the wafer from damage in subsequent process steps. By means of thermal oxidation or electrochemical anodizing, a high-quality SiO2 layer can be uniformly grown on the wafer surface. This "protective film" provides a solid foundation for subsequent photolithography and doping processes.
Photolithography etching: The art of drawing circuit patterns
Photolithography is one of the most artistic processes in semiconductor manufacturing. It takes advantage of the photoresist's sensitivity to light to precisely transfer the pattern designed by the chip designer to the wafer. During the lithography process, the photoresist is uniformly applied to the surface of the wafer and chemically changes the photoresist in a specific area through the masking effect of the mask. Subsequently, the portion of the wafer that is not protected by the photoresist is removed by an etching process to form the desired circuit pattern. The process is like carving a work of art in a microcosm, where every detail counts.
Figure: Inventory of the five major processes of semiconductor manufacturing
Doping process: Giving life to semiconductors
The doping process is one of the most critical steps in semiconductor manufacturing. By injecting specific impurities (dopants) into a wafer, it is possible to modify its conductivity to give it the properties of N-type or P-type semiconductors. These dopants form conductive channels or insulating regions inside the wafer, making it possible to realize the functionality of semiconductor devices. Ion implantation is the most commonly used method in the doping process, which uses a high-energy ion beam to bombard the surface of the wafer, injecting the dopant into the wafer and diffusing it to the desired depth.
Thin-film process: building bridges with multi-layer structures
The thin-film process is a key technology for building multilayer structures in semiconductor manufacturing. By depositing various thin-film materials (such as insulating layers, conductive layers, etc.) on wafers, complex circuit structures and functional areas can be formed. These thin-film materials not only have excellent electrical, thermal, and mechanical properties, but also interact with other materials in subsequent processes to jointly realize the functions of semiconductor devices. Chemical vapor deposition (CVD) and physical vapor deposition (PVD) are two of the most commonly used methods in thin film processes, and they support the fabrication of semiconductor devices by precisely controlling the thickness, composition, and uniformity of thin films.
The five cornerstones of semiconductor manufacturing—wafer preparation, oxidation, photolithography, doping, and thin film processes—together constitute a complex system for semiconductor chip manufacturing. These process steps are interdependent and mutually influential, and each step is crucial. With the continuous progress and innovation of science and technology, the semiconductor manufacturing process is also constantly optimized and improved, injecting infinite possibilities into the development of future science and technology. We believe that in the near future, semiconductor technology will continue to lead the trend of science and technology and contribute more wisdom and strength to the progress of human society.
