Teflon spin-coating

The mixture was initially filtered through a 0.2 pm pore diameter teflon filter. It was spin-coated onto a silicon wafer previously sprayed with hexamethyldisilazane and baked for 40 seconds at 90°C and 90 seconds at 110°C, forming a 500 nm resist film. The resist film was exposed to ArF excimer laser light, heat treated for 90 seconds at 110°C, and cooled to ambient temperature. It was then dipped in 2.38% aqueous tetramethylammonium hydroxide solution for 60 seconds for development where it formed a 1 1 line-and-space pattern. The wafer as developed was... 

The novolac resin used in NPR formulations was a proprietary resin manufactured by Polychrome Corp. to Bell Laboratories specifications. Samples of NPR containing 20% and 50% PMPS were prepared in Hunt Photoresist Thinner (mixture of ethoxyethyl acetate, butyl acetate and xylene), filtered through 1 /un Teflon filters and spin coated onto undoped silicon wafers to give films 9,000 A thick. All films were prebaked at 110 C for 2 hr. Film thickness was measured directly by a Nanometrics Nanospec AFT microarea thickness gauge. Alternatively, the samples were coated with a thin layer of aluminum and measured mechanically with a Dektak. 

Germanium ATR crystals were coated with thin polymer films by spin-coating techniques. A commercially available spin coater (Headway Research, Inc., Model EC-101) with a specially designed Teflon chuck was used to hold the Ge crystal. For example, Biomer--the medical polyurethane supplied by Ethicon (Somerville, NJ)--was applied in three to four coats in a 1.5 percent solution of cyclohexanone to produce stable films with thickness less than the depth of penetration of the IR field. 

All three commercial amorphous fluoropolymers. Teflon AF, Hyflon AD, and Cytop posses a unique set of properties. All dissolve in fluorinated solvents and thus may be spin coated to produce thin hlms and coatings. The polymers may also be extruded and molded using traditional polymer processing techniques. Note that the polymers are not soluble in hydrocarbon solvents or water and retain the chemical and thermal stability of perfluorinated polymers such as Teflon . These polymers have lower density than the well-known semicrystalline perfluorinated polymers such as pTFE that results in lower refractive index, lower thermal conductivity, higher gas permeability, and lower dielectric constant. The polymers are transparent and have excellent mechanical properties below their Tg due to their amorphous character. The presence of a heterocyclic ring in the polymer backbone of these materials is key... 

The synthesized diblock copolymers were dried in a vacuum oven at 60 °C overnight. Then 10 %wt stock solutions were prepared in anhydrous toluene and filtered with 0.45 xm Teflon (PTFE) Alters. Micrometer thick copolymer Aims were spun, drop-or blade-coated, typically using 3.5 xl of copolymer solution per square centimeter. Films prepared by spin coating were spun at 200-700rpm for 45 s. 

The reaction between TDI and castor oil is exothermic and bubbles are produced in the reaction mixture (castor oil contains a few tenths of a percent volatile material that will evaporate as the temperature of the reaction mixture goes up. Some of the bubbles produced are trapped in the mixture as the viscosity increases. Stirring with a teflon coated magnetic spin bar also produces some bubbles). In order to produce elastomers that are bubble free, the reaction is carried out in two stages. 

The only volatile impurity at this point is bicyclo[2.2.1]-hepta-2,5-diene. If the irradiation has been carried out for a sufficient period of time, the amount of diene present is less than 2%. Distillation through an efficient column will remove most of the diene [bicyclo[2.2.l]hepta-2,5-diene, b.p. 91° (760 mm.), 51° (200 mm.)]. Traces of acid3 and noble metal ions and complexes4 may cause quadricyclane to isomerize to the diene. The checkers used a 60-cm. Teflon-coated spinning-band column... 

A Teflon-coated, heavy duty, oval-shaped spin bar was used by the submitters for efficient stirring. 

Teflon AF can be extruded and injection or compression molded It can be formed by spin casting or applied from solution by spray coating or direct application [5] Its extremely low refractive index and its solubility make it highly useful as a coating for the core of optical fibers... 

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