In the past few years, global wafer capacity expansion, including China, and investment in new processes have ushered in a period of prosperity for semiconductor equipment manufacturers. Every financial report is very good. Among them, ASM performed exceptionally well. Digital growth has rushed into the list of the world's top ten semiconductor equipment manufacturers in 2019. According to General Manager Xu, the sales performance of China ASM has tripled in 2018 and 2019. Sales in 2019 increased four times compared to 2017.

Xu Lai analyzed that one of the driving forces for the rapid growth of the ASM global market is the rapid growth of the company's main product, atomic layer deposition (ALD).

Atomic layer deposition technology is a chemical vapor deposition method based on orderly, surface self-saturation reaction. In layman's terms, layers of sub-nanometer thick film can be evenly "wrapped" on the surface of an object. This technology can realize the uniform coating of various functional materials on the sub-nanometer scale, and well solve the defects and uniformity problems existing in the current functional devices.

The main principle of atomic layer deposition is shown in the figure: the biggest feature of ALD is to effectively decompose the traditional chemical gas phase reaction into two and a half reactions. When the target component is AB, the precursor a is introduced into the cavity first. , It will react with the surface groups of the substrate and uniformly adsorb on the surface of the substrate. Due to the interaction between the two substances A and B, when A is completely adsorbed on the surface, the excess A needs to be blown away with an inert gas. Then, another precursor B is introduced to react with the A layer on the surface, and at the same time, an inert gas is required to blow B away. These processes constitute a growth cycle to form a uniform film, and the thickness of the film grown in each cycle is consistent, and precise control of the film thickness can be achieved by controlling the number of growth cycles. Therefore, atomic layer deposition is a precise and controllable thin film growth technology.

Atomic layer deposition technology has been applied for the first time in the development of electroluminescent thin film devices. In 1974, Tuomo Suntola discovered the advanced ALD thin film deposition technology and named it Atomic Layer Epitaxy (ALE). The AL2O3 layer was prepared by this method. And apply it to flat panel displays.

Since then, ALD technology has continued to advance, and the development of the semiconductor industry has become an important driving force for breakthroughs in ALD technology. The rapid development of microelectronic devices requires the integration of electronic devices under the premise of ensuring accuracy, and presents the characteristics of "small and precise". Therefore, during the deposition process, it is not only necessary to meet the requirements of various functional materials, but also to precisely control the thickness of the film to form a uniform surface. At the same time, the stability of the device requires that defects such as holes should be minimized during processing. Technology satisfies these requirements well. In the field of microelectronics, ALD has been extensively studied as a potential technology for depositing high-K (high dielectric constant) gate oxides, high-K storage capacitor dielectrics, ferroelectrics, and metals and nitrides for electrodes and interconnections.