Thin film deposition techniques/processing spraying processes

After the precursor stock solution is prepared, various techniques can be used to coat the substrate, depending on the solution viscosity, required film thickness and coverage. The most common methods in the semiconductor industry are spin- and dip-coating. Other processes that are used for deposition include spray coating and stamping. A summary of the uses, limitations, and advantages of the various thin film deposition methods is reported in Table 2.2. 

Some review articles pertaining to spray pyrolysis processing and the range of thin films deposited by this technique for various appKcations have appeared in the literature. Viguie and Spitz [74] have classified chemical spray deposition process according to the type of reaction. A most recent survey on thin-film materials prepared by spray pyrolysis and advances in the field, especially different atomization techniques, was presented [12j. The critical operations for the spray pyrolysis technique are (1) preparation of uniform and fine droplets and (2) the controlled thermal decomposition of these droplets in terms of environment, location, and time. 

Smdies on techniques for thin film deposition divide these into two groups, depending on the nature of the deposition process. Physical methods include physical vapor deposition (PVD), laser ablation, molecular beam epitaxy and sputtering. Chemical methods comprise of gas phase and solution deposition. The gas phase techniques include chanical vapor deposition (CVD) and atomic layer epitaxy (ALE). Spray-pyrolysis deposition, sol-gel, spin-coating and dip-coating are techniques based on solution deposition. 

Thermal spray, laser deposition, physical vapor deposition, and magnetron sputtering are physical processes that are used for fabrication of electrolyte thin films. Sputtering is a reliable technique for film deposition and is being used in industry... 

The microstructure was realized by a dry-film photoresist technique and based on established techniques from printed circuit board technology [142], Dry resists are available as thin films, e.g. of thickness 50 or 100 pm. The resist films are encased in other polymer materials which are later removed. The resist films can be deposited on various base materials such as silicon or polymers giving mechanical stability. Lamination is carried out with a roller laminator. Then, exposure is made and spray development without any solvents follows. The process steps can be repeated at multi-laminated structures. Closed structures can be made in this way. 

Chen, C.H., Varhaug, K.N., Schonman, J. Coatings yttria-stabilized-zirconia (YSZ) thin films on gadolinia-doped ceria (GCO) by the electrostatic spray deposition (BSD) technique. J. Mater. Synth. Process. 4, 189-194 (1996)... 

Many techniques have been used to prepare ZnO-based thin films and nanostructures, such as CVD, electron beam evaporation (EBE), MBE, pulsed laser deposition (PLD), sol-gel, spray pyrolysis, sputtering, and vapor phase growth. To prepare ZnO films or nanostructures, thermal oxidation of Zn and ZnS in air has also been used [124]. However, as for ZnS nanocrystals, wet methods, in this case wet oxidation, are still important techniques for SC processing [112]. 

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