Thin film deposition coatings have been greatly involved in the fabrication of modern optical systems such as waveguides, filters, superreflective mirrors, antireflective lenses, etc… Those high-tech optical applications often require a coating of thickness in precise control and of high quality, meaning high packing density, good surface uniformity, low defect density, good mechanical properties such as good adhesion with underlying substrate, acceptable scratch, abrasion resistance, low stress, low crack density, and thermally and environmentally stable. Atomic layer deposition is an enabling technology that can produce such thin films. Specifically, Atomic Layer Deposition has great advantages in: 1) coating of complex objects that are difficult or impossible using other methods like PVD; 2) engineering of novel optical materials; 3) auxiliary
process to provide or improve the crucial features in film stacks; 4) coating by batches and of large areas.
Within the display industry, the classical ALD application is thin film electroluminescent (TFEL) displays, usually ZnS.
Transparent coating as protection or passive layer for flexible electronics, photovoltaics, plasmonics and etc: TiO2/ZnO/Al2O3/ZrO2/HfO2/SiO2
ALD deposited film (stacks) can enhance reflectivity or as anti-reflective (AR) coatings: TiO2/ZnO/Al2O3/ZrO2/Ta2O5
ALD enables dielectric materials coatings for wave guides, Inverse opal photonics devices and etc: TiO2/ZnO/ZrO2/Ta2O5/GaP
Photonic bandgap engineering in germanium inverse opals by chemical vapor deposition. Adv.Mater. 2001, 13, 1634–1637.
TiO2 inverse opals fabricated using low-temperature atomic layer deposition. Adv. Mater. 2005, 17, 1010–1013.
Atomic layer deposition for industrial optical coatings, Jarmo Maula, Chinese Optics Letters 2010, 8, 53-58
Impact of atomic layer deposition to nanophotonic structures and devices, Frontiers in Materials 2014, 1, 1-15