|AVS 57th International Symposium & Exhibition|
|Thin Film||Wednesday Sessions|
|Session:||ALD: Nanostructure, Magnetics and Biological Applications|
|Presenter:||V.M. Bright, University of Colorado at Boulder|
|Correspondent:||Click to Email|
Atomic Layer Deposition (ALD) can be effectively used to deposit custom-designed, multi-material layers with atomic resolution on any micro- or nano-scale device surfaces. The nano-scale ALD coating can protect the devices from electrical short, charge accumulation, moisture-induced adhesion, wear, corrosion, creep, fatigue or anodic oxidation during prototyping or long-term product life. ALD films for N/MEMS achieve these goals similar to what CVD Si3N4 has been for CMOS. As MEMS scales further shrink toward nano-electro-mechanical systems (NEMS), ALD processes offer a new strategy for depositing conformal and precise films that may have important applications as a novel dielectric, a sacrificial layer for gap control in nanofabrication, or as a structural layer for NEMS realization.
ALD relies on sequential, self-limiting surface reactions to deposit ultra thin, conformal films. The following characteristics of ALD films and processes make them flexible and multifunctional, and represent their appeal for N/MEMS: ALD film thicknesses can be precisely deposited from a few Å to hundreds of nm; ALD films can be deposited at temperatures ranging from 33ºC to over 200ºC; ALD films are pinhole-free, dense, smooth and highly conformal; ALD films can be deposited on silicon, polysilicon, silicon nitride, metals, polymers, and ceramics; ALD films can be conformally deposited on any size or shape device or any substrate; ALD can coat high surface area to volume ratio structures with complex geometries; ALD can deposit dielectric or conductive layers; ALD can deposit hydrophobic or hydrophilic layers covalently bonded to the surface; ALD can deposit on lithographically defined selective areas; ALD films can be micromachined to create nano-scale gaps and free standing structures; ALD coating process’ deposition rate can be high, e.g. 0.5 nm/min at 177oC for Al2O3.
These ALD techniques for N/MEMS, pioneered at the University of Colorado – Boulder, represent breakthrough in nano-scale processes that can be used to fabricate custom-designed, multi-material layers with atomic resolution. The ALD processes developed are proven, mature, and are available to serve the N/MEMS community.