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Laurell Technologies WS-400 spin coater used to apply photoresist to the surface of a silicon wafer. Spin coating is a procedure used to deposit uniform thin films onto flat substrates. Usually a small amount of coating material in liquid form is applied on the center of the substrate, which is either spinning at low speed or not spinning at all.
There are four basic parameters that are involved in spin coating: solution viscosity, solid content (density), angular speed, and spin time. [13] A range of thicknesses can be achieved by spin coating. Most commonly the thicknesses range from 1-200 μm. The main properties that affect the thickness of the film are viscosity and spin speed.
A familiar example is the household mirror, which typically has a thin metal coating on the back of a sheet of glass to form a reflective interface. The process of silvering was once commonly used to produce mirrors, while more recently the metal layer is deposited using techniques such as sputtering .
The Stöber process is a well-studied example of polymerization of an alkoxide, specifically TEOS. The chemical formula for TEOS is given by Si(OC 2 H 5) 4, or Si(OR) 4, where the alkyl group R = C 2 H 5. Alkoxides are ideal chemical precursors for sol–gel synthesis because they react readily with water.
The first self-cleaning glass was based on a thin film titania coating. [3] The film can be applied by spin coating of organo-titanate chelated precursor (for example titanium iso-tetrapropoxide chelated by acetylacetone), followed by heat treatment at elevated temperatures to burn the organic residues and to form the anatase phase.
Spin Coating and solvent evaporation methods are capable of producing large areas of particles, but with limited control over the layer homogeneity or thickness. [ 3 ] Solvent evaporation is accomplished via drop coating, and is arguably the simplest method to produce a monolayer of nanospheres, as the spheres are simply dropped onto the ...
Spin casting is also used to manufacture large telescope mirrors, where the natural curve followed by the molten glass greatly reduces the amount of grinding required. Rather than pouring glass into a mold an entire turntable containing the peripheral mold and the back pattern (a honeycomb pattern to reduce the mass of the finished product) is ...
The record-holding CZTS solar cells is made by spin coating a hydrazine-based slurry. [11] Due to its reducing character, hydrazine can stabilize sulfide and selenide anions in solution without adding impurities into the mix. [12] To prevent defect formation, copper-poor and zinc-rich solutions were used.