Nanoimprint lithography patterning with

Figure 6.12 Preparation of patterned LBL assemblies (a) by nanotransfer printing and (b) by sequentially using nanoimprinting lithography, CD SAM formation, and lift-off process. Reprinted with permission from Crespo-Biel et al. (2006).

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... 

Moritz and coworkers have studied the coupling between the dots obtained by deposition of Co/Pt multilayers on prepattemed Si substrates [3.122,123]. Two patterning process were compared (a) electron-beam lithography followed by direct RIE [3.124], and (b) nanoimprint lithography followed by lift-off and dry RIE of silicon [3.125,126]. Subsequent deposition of a magnetic material (Co—Pt) leads to arrays of singledomain dots with a perpendicular magnetization. 

Nanoimprinting A master stamp is used directly for hot embossing of a substrate, usually made of a polymer. This allows the stamp to produce many patterned substrates. Although there is no diffraction hmit here, hot embossing has been applied mainly for low-resolution applications, in various fields such as miniaturized total-analysis Systems (p.TAS), microfluidics, and microoptics. UV-nanoimprint lithography corresponds to contact printing with UV exposure. 

Common to all NIL techniques is the requirement for a master stamp or template. The master is usually fabricated on silicon, glass or other rigid wafer substrate. For a nanoimprint process, the master must be patterned with nanoscale features using electron beam lithography. 

Fig. 3.16 Embossing or nanoimprint lithography procedure. A hard or soft mold is in contact with surface of a film (a) A pressure is accomplished on the hard mold or a conformal contact is realized for the soft one in order to transfer the features of the mold on the film surface (b) sometimes at this stage a thermal treatment is necessary in order to soften the film and allow abetter transfer of the patterning. Mold is removed (c) A final etching process can be performed to reduce the residual layers between the transferred structures (d)...

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