Direct lithography process

It was found that 5-nm-thick resist-mask polysilane films worked well in a direct lithography process on silicon substrates, resulting into a line width of 40 nm prepared by scanning probe microscope lithography, using a carbon nanotube tip.57 Thin PMPS films of 6—8 nm, with a molecular weight of 30,000 were prepared by spin casting and cured at 150°C to obtain a smooth surface. It has been interpreted that moisture was essential for the oxidation of the polysilane. The proposed mechanism involved dissociation of Si-Si bonds in polysilane by the electron injection from the carbon nanotube tip catalyzed by moisture. 

Chemically amplified resists are quite effective in improving pattern sizes in photofabrication. However, optical limitations in resolution must be overcome to improve further progress. Several processes contribute to improving the resolution of photofabrication. In this chapter, immersion, double-patterning, multipatterning maskless, multielectron beam, and direct self-assembly lithography processes are introduced. 

With the same material, compound 9, a directly printed distributed feedback (DFB) laser [75, 76] was obtained by room-temperature nanoimprint lithography [55-57]. The laser exhibited a single-mode emission peaked at 637 nm, with a full width at half-maximum of less than 0.7 nm and a pump threshold of 140 ttJcm 2. -pjjg lithography process allowed the pattern to be transferred with high precision... 

Although e-beam lithography can give excellent spatial control of functional microdomains, this direct-write patterning process is not time-efficient for large-area integration of functional devices. Techniques for rapid patterning of functional nanostructures are thus needed for real-time applications. Ober et al. [106-108] have successfully developed a novel block copolymer... 

Before the invention of the planar transistor, many photoresist processes were developed for the manufacture of circuit boards. Experience gained in this area was rapidly transferred to silicon processing, and much of the early work in integrated circuit lithography can be traced directly to circuit board manufacturing. 

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