Spin coating is a procedure used to apply uniform thin films to flat substrates. An excess amount of a solution is placed on the substrate, which is then rotated at high speed in order to spread the fluid by centrifugal force. A machine used for spin coating is called a spin coater, or simply spinner.
Rotation is continued while the fluid spins off the edges of the substrate, until the desired thickness of the film is achieved. The applied solvent is usually volatile, and simultaneously evaporates. So, the higher the angular speed of spinning, the thinner the film. The thickness of the film also depends on the concentration of the solution and the solvent.
Spin coating is widely used in microfabrication, where it can be used to create thin films with thicknesses below 10 nm. It is used intensively in photolithography, to deposit layers of photoresist about 1 micrometre thick. Photoresist is typically spun at 20 to 80 revolutions per second for 30 to 60 seconds.
Famous quotes containing the words spin and/or coating:
“In tragic life, God wot,
No villain need be! Passions spin the plot:
We are betrayed by what is false within.”
—George Meredith (1828–1909)
“The world is eaten up by boredom.... You can’t see it all at once. It is like dust. You go about and never notice, you breathe it in, you eat and drink it. It is sifted so fine, it doesn’t even grit on your teeth. But stand still for an instant and there it is, coating your face and hands. To shake off this drizzle of ashes you must be for ever on the go. And so people are always “on the go.””
—Georges Bernanos (1888–1948)