There has been much new advancement in the nano-technology field on a international level in recent years. The new advancements have drawn a increasing interest in nanometer scale surface coating. Ultra thin film coatings can be used in a wide range of applications as lubricants, anti-stiction layers, molecular glues, coupling agents or adhesion layers. The mentioned molecular coatings are used to modify material surface properties. The traditional coating deposition methods consist of a set of sequential wet baths. The wet processing method is complex and limits the ability of molecular coating in many MEMS applications. The use of liquid precursors has extremely limited bath life, which cause the method to be highly expensive and have low product ability. In this paper a new surface coating technique a new surface coating technique will be discussed, which is called Molecular Vapor Deposition (MVD). This new method has proven to overcome the shortcomings of the liquid phase method and has single handedly improved changed the ability of surface coatings.
Molecular Vapor Deposition (MVD) is a unique nanotechnology technique that allows for room temperature vapor deposition of organic and organometallic molecules. MVD technology enables the growth of ultra-thin films with a wide range of functionality on a broad spectrum of substrates. This innovative technique has allowed many new emerging applications with small feature sizes that where very difficult or impossible to produce using traditional liquid synthetic techniques. MVD is very versatile and is an ideal process for modifying surface properties. Films that are created using MVD can serve as hydrophobic, hydrophilic, biocompatible, protective, or reactive coatings. The MVD process takes place in a vacuum and when it is combined with Applied MicroStructures advanced surface preparation and adhesion enhancement techniques, the extent of surface coverage and coating conformability can each approach 100%.
Molecular Vapor Deposition was developed by a company called Applied Microstructures Inc. (AMST) which deals with the development of Molecular Vapor Deposition processes. Its MVD processes are applied to nano-devices and micro-sensors that deal with automotive airbag accelerometers and cellular phone microphones. AMST currently markets two machining tools; the MVD 100 which provides automated deposition of organic and composite surface coatings; and the MVD150 system, which offers manufacturing capacity and automation. The company also offers MVD NanoFilms that are customized nano-scale thin films used to modify surface properties of substrates, and process chemicals for surface modification and for surface functionalization of various substrates and materials. It provides MVD equipment and contracted deposition services for MEMS, nano-bio, nano-imprinting, and hard disk applications. The company was found in 2003 and is based out of San Jose, California.
Applications of MVD
In MEMS applications, MVD molecular films are typically self-assembled mono-layers (SAMs) with very low work of adhesion and are used as anti-stiction coatings. In Nano-imprint Lithography applications, MVD films are used as very thin and conformal release layers between the stamp and polymer materials. In Inkjet applications, MVD films are used to prevent ink accumulation on the nozzle face plate to ensure unrestricted ink flow. In Bio-MEMS, hydrophilic and biocompatible MVD films can be used to improve wetting or to prevent protein adsorption. In Biotechnology applications, MVD films are used to create surface anchors for subsequent coatings.
In SAMS coating MVD allows for the creation of molecular organic coatings which are denser and more durable than those obtained by current liquid or vapor-phase methods. This improvement has been achieved using a sequential or layered vapor deposition scheme of two different molecular films. The first...