Thickness loss, spin coating

Imaging studies were done on copolymers prepared by the polymer modification route because of the availability of the precursor polymers of various molecular weights. The protected copolymers were compounded with triphenylsulfonium hexafluoroantimonate (13% w/w) in cyclohexanone. One micron thick films were spin coated on NaCl plates, baked at 140°C for 5 minutes to expel solvent and then subjected to infrared spectroscopic analysis before and after exposure. Exposure to 18 mJ/cm2 at 254 nm caused no change in the infrared spectrum. However, when the films were baked at 140°C for 120 sec. following exposure, deprotection was quantitative based on loss of the characteristic carbonate C = O absorption and... 

The most widely used technique for producing thin films of polymeric material is spin coating from solution. This technique is widely used in microelectronics fabrication to produce thin films of photoresist for photolithographic processes (Chapter 2). For this application, the thickness and uniformity of the photoresist must be accurately controlled, and to this end precision spin-coating machines have been developed offering accurate acceleration and spin speeds typically between 1000 and 10000revmin The requirement of polymeric thin films for optical purposes are very similar, and spin-coating techniques have been used to produce exceptionally low-loss structures [139]. 

---