Déformation photoinduite dans les films minces contenant des ...

Chapter 5. Nanostructured hybrid systems 146sampleholdery-translationyBabinetNG4 4 mmlaser Kryptonz-translationzx(a)sample holderpastel-00527388, version 1 - 19 Oct 2010(b)PMMAthin filmFigure 5.8: Gold coated PMMA-DR1: lithography mask. (a) Experimental setup (b)Detail of the sample holder and of the first order diffraction spots used to align themask and the laser beam. Laser beam power intensity = 5 mW/mm 2 , λ = 477 nm,exposure time = 30 min.5.2.2 Optical pattern tansfermaskThe optical nanostructuration processes presented in the previous sections are potentiallywell adapted for the patterning of masks and moulds for nanolithography andnanoimprinting. The fabrication processes adopted to realize these elements are generallyextremely slow, since the desired pattern must be written, using a focused beam,feature by feature, in order to guarantee accuracy, which leads to low yields and to bigcosts [12, 13]. Moreover, surface treatment is needed for the masks to be used in acontact pattern transfer application (such as soft lithography, nanoimprinting, etc.), inorder to eliminate contact defects and to preserve the mask lifetime.The possibility to use photostructured azo-containing thin films as masks for nanolithographyprocesses has been shown in [14] using non contact lithography. In this case, thepatterned mask is projected 1:1 on a photochromic film.