Lithography equipment

Specialized eqnipment is required that is not available in all laboratories. This is particularly true of the high-end lithography equipment employed in several common approaches for patterning thin-fitm materials at the submicron level. 

The LB film depositions were performed using a Joyce-Loebl Langmuir Trough IV equipped with a microbalance for measurement of the surface pressure by the Wilhelmy plate method. Filtered deionized water with a pH of 7 was used for the subphase. For the electron beam lithography study, PMMA was spread on the water surface from a dilute benzene solution ( 10 mg PMMA in 20 ml benzene). The novolac/PAC mixtures were spread from solutions ( 20 mg solids in 10 ml solvent) of isopropyl acetate. For the fluorescence studies, the PMMA/PDA mixture was spread on fee water surface from a dilute benzene solution (1.75 mg PDA and 8.33 mg PMMA in 20 ml benzene). Prior to compression, a 20 min interval was allowed for solvent evaporation. The Langmuir film was compressed to the desired transfer pressure at a rate of 50 cm2/min, followed by a 20 minute equilibration period. The Cr-coated silicon wafers and quartz wafers were immersed into fee subphase before... 

Optical Lithography. Lithographic processes can be classified according to the energy used to expose the resists and the equipment necessary to accomplish the process. Image quality depends on the exposure method, hardware, and resist material. In optical lithography, the resist is exposed to radiation within the near- to deep-UV region (200-450 nm). 

Particularly in 2D systems, control over the self-assembly of colloidal templates has offered a versatile way to produce patterned surfaces or arrays with a precision of few nanometres. Diblock copolymer micellar nanolithography (dBCML) is a versatile method that uses homopolymers or block copolymers for the production of complex surface structures with nanosized features [69], In contrast to other approaches like electron-beam lithography (EBL) and photolithography, dBCML does not require extensive equipment. In fact, it is commonly used in the fabrication of data storage devices and photonic crystals, in catalyses [70], and for the design of mesoporous films and nanoparticle arrays [71]. 

Lithography In order to precisely resolve the nanometer structures in microelectronics, various enhancement techniques have been applied to the current optical exposure tools that are equipped with deep UV light (193 nm wavelength). These enhancement techniques include phase-shift masks and immersion lenses (putting a liquid between final lens of the stepper and the wafer). The trade-off for the high resolution of modern steppers is an extremely small depth of focus (DOF) that is around 0.5pm over a typical field size of... 

For the next generation of submicrometer ground rules, a fourfold reduction in alignment and other errors will be necessary. Almost every type of mask aligner—contact/proximity, projection scanner, and step and repeat—is used for some of the lithography steps in the fabrication of state of the art integrated circuitry today. For a detailed description of mask alignment equipment we refer to the literature [2, 3]. 

X-ray, e-beam and ion beam lithography. In the IC industry, continuous improvements in optical lithography have postponed the industrial adoption of alternative lithographies. Because of the huge financial investment in photolithography equipment, this situation will remain unchanged for at least another five to 10 years. 

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