Coatings on High Aspect Ratio Structures

Atomic Layer Deposition of Nanostructured Tunable Resistance Coatings: Growth, Characterization, and Electrical Properties

“…This difference may stem from the much higher deposition rate for the ALD Mo (~10 Å/cycle) versus the ALD W (~5 Å/cycle) under similar growth conditions, especially in light of the exponential relationship between resistivity and metal content. The range of resistivity values provided by these coatings (~10 4 -10 10 Ohm-cm) is particularly useful for applications in electron multipliers (2, 3) and charge drain coatings (3,14,15). In comparison with W growth on Al 2 O 3 (Figure 4c), the mass uptake for the Mo growth on Al 2 O 3 (Figure 4a) increases monotonically and smoothly with the number of ALD Mo cycles, especially in the early nucleation regime of the first 1-3 ALD cycles.…”

“…We utilized these nanocomposite coatings to functionalize capillary glass array plates to fabricate large-area MCPs suitable for application in large-area photodetectors (2,3,13). In addition, we have applied these films as charge drain coatings in MEMS devices for a prototype electron beam lithography tool, and obtained high resolution electron beam patterns without charging artifacts (11,14).…”

“…Nanostructured composite thin film materials comprised of mixed conducting and insulating components have been utilized in a wide variety of applications including resistive layers for electron multipliers such as microchannel plates, resistive memories, electro-chromic devices, biomedical devices, and charge-dissipating coatings on microelectromechanical systems (MEMS) devices and electron optics (1)(2)(3)(4)(5)(6). By varying the precise composition of the mixture, the electrical, optical, and physical properties of the composite coatings can often be tuned over the full range of the individual components, and can sometimes yield unique properties distinct from either of the constituents.…”

“…By alternating between the ALD chemistries for two materials (e.g., a metal and a metal oxide), we can synthesize nanostructured composite coating. The thickness of the coating is controlled by the total number of ALD cycles performed, and the composition is dictated by the relative ratio of the ALD cycles executed for the two components (1,3).…”

Conformal SiO2 coating of sub-100 nm diameter channels of polycarbonate etched ion-track channels by atomic layer deposition

“…Tailored coating with various materials such as metals (e.g., Pt) or oxides (e.g., ZnO, Al 2 O 3 , TiO 2 ) can be used to adjust specific surface properties such as hydrophilicity or catalytic activity. Conform ALD coatings have been reported for various porous materials including powders [18] and porous membranes such as anodic aluminum oxide (AAO) [19][20][21][22][23][24] and track-etched membranes [25][26][27][28]. For example, channels with diameters of about 80 nm and lengths of about 700 nm of AAO membranes were successfully coated with a 20 nm thick SiO 2 layer through the consecutive pulsed appliciation of 3-aminopropyltriethoxysilane, water and ozone [22].…”