The number of ALD applications has grown exponentially over the past few years. Nowadays, in conjunction with Moore’s law and constantly decreasing IC (integrated circuit) device size, ALD is the only method with which the functional material layers thin enough can be manufactured while still retaining the highest quality, uniformity, conformality, and structural integrity on the nanometer-scale features and high aspect ratio structures common in today’s memory, logic, and hard drive components. In short, ALD enables our modern mobile communication devices and increasingly compact and efficient computers.
Atomic Layer Deposition (ALD) is an advanced thin film coating method which is used to fabricate ultra-thin, highly uniform and conformal material layers for several applications. ALD uses sequential, self-limiting and surface-controlled gas phase chemical reactions to achieve control of film growth in the nanometer/sub-nanometer thickness regime. Due to the film formation mechanism – the gases won’t react until in touch with the surface which means the film growth proceeds by consecutive atomic layers “up” from the surface – the ALD film is dense, crack, defect and pinhole-free and its thickness along with structural and chemical characteristics can be precisely controlled on atomic scale. The ALD process is digitally repeatable and it can be performed at relatively low temperatures. This gives the possibility to construct not only single material layers but also doped, mixed, or graded layers and nanolaminates. Low process temperature on the other hand allows coating of sensitive materials also such as plastics and polymers. The list of ALD materials is wide, ranging from e.g. oxides, nitrides, fluorides, carbides, and sulfides to ternary compounds, metals (including noble ones), hybrid materials and polymers.
In addition to IC component manufacturing, other large scale industrial applications for ALD can be found in sensor, LED and other III-V devices, and MEMS (microelectromechanical systems) manufacturing. ALD films are also used in optics and optoelectronics, anti-tarnishing and corrosion protection, and renewable energy applications such as solar power. The ALD method offers novel solutions for energy storage and production (e.g. advanced thin film batteries and fuel cells), biocompatible and bioactive surface functionalization of medical devices and implants, ecological packaging materials, moisture and gas-tight encapsulant layers, decorative coatings, and hydrophobic/hydrophilic coatings.