Atomic Layer Deposition (ALD) is an advanced thin-film preparation technology. It achieves atomic-scale thickness control through layer-by-layer, self-limiting surface reactions. In recent years, with the rapid development of micro/nano fabrication, ALD has shown strong application potential in semiconductors, optoelectronics, new energy and other fields because of its excellent uniformity, conformality and thickness controllability.
Micro/nano fabrication refers to technologies used to manufacture structures and devices at micrometer or nanometer scales. It is widely used in integrated circuits, MEMS, sensors and related fields. With its unique advantages, ALD has become an indispensable process method in micro/nano fabrication.
ALD introduces precursor gases alternately so that thin films grow layer by layer on the substrate surface. Even in high-aspect-ratio structures, such as nanopores and three-dimensional features, ALD can provide uniform coverage. This property is especially important in micro/nano fabrication. For example, high-k dielectric layers deposited by ALD in FinFET transistor manufacturing can effectively improve device performance.
Micro/nano fabrication places extremely strict requirements on film thickness. ALD controls film thickness precisely through the number of reaction cycles, with control reaching the sub-nanometer level. This meets the demanding material requirements of nanoscale devices. For example, aluminum oxide films deposited by ALD can be used as efficient barrier layers in flexible electronic devices, helping extend device lifetime.
Conventional thin-film deposition methods such as CVD usually require high temperatures. ALD can be performed at low temperature, and in some cases even near room temperature. This makes it suitable for temperature-sensitive micro/nano structures, including organic electronic devices and biosensors.
As micro/nano fabrication moves toward smaller dimensions and higher integration, ALD will play a greater role in emerging memories such as MRAM, quantum devices and biomimetic nanomaterials. At the same time, the development of new precursors, higher deposition rates and lower process costs will remain important research directions for ALD technology.
As one of the core technologies of micro/nano fabrication, atomic layer deposition will continue to drive progress in nanotechnology and high-end manufacturing, providing key process support for next-generation electronic, optoelectronic and energy devices.
