Stencil masks

The preparation of structured polystyrene brushes was carried out following the same procedures, only the irradiation was performed through a stencil mask with circular openings of 800 nm radius that was placed on the NET covered substrate. 

Using a stencil mask with slits varied between 300 and 70 nm nanometer size structured polymer brushes were created following the same procedure, resulting in a one-to-one translation of the mask patterns. 

Fig. 9.22 a) SEM micrograph of polystyrene brushes generated via SIP on a substrate that was irradiated through a stencil mask with a coarse grid with 50 pm periodicity. Each square contains an array of circular holes of 1.5 pm dots (2.5 pm periodicity), b) SPM... 

Fig. 9.23 SPM micrographs of PS brushes generated by SIP on a chemical nanolithography substrate prepared by a stencil mask with a slit pattern. The height profiles below the images show an average profile along the...

Figure 7. Co/Pt multilayer irradiated through a stencil mask (a) MFM image, and (b) and (c) line scans from lower left and upper right parts, respectively, along rows of dots as indicated by the white arrows.

Terris BD et al (1999) Ion-beam patterning of magnetic films using stencil masks. Appl Phys Lett 75 403-405... 

Fig. 14 SEM photographs of polyimide patterns with CVD tetravinylsilane film as an etch barrier (a) a stencil mask used, (b) (b),(c) polyimide patterns of (PMDA-ODA) vapor deposited.

Stencil mask in close proximity to the wafer Wafer... 

The second way to employ ion beams in lithography is to place a stencil mask in close proximity to a surface and irradiate the mask with a collimated beam of ions. This is referred to as proximity ion-beam lithography, and it is a 1 1... 

The third way to employ ion beams in lithography is to combine the first two techniques and use an ion optical column to project the image of the pattern of a stencil mask onto a wafer. This is called ion projection lithography (IPL), which was pioneered at Ion Microfabrication Systems (IMS) of Austria in the late 1980s.Because IPL is the most technologically important of the three versions of ion-beam lithographies, we shall discuss it in much greater detail. 

A. Erhmann, A. Eisner, R. Liebe, T. Struck, J. Butschke, F. Letzkus, M. Irmscher, R. Springer, E. Haygeneder, and H. Loschner, Stencil mask key parameter measurement and control, Proc. SPIE 3997, 373 384 (2000) R. Kaesmaier and H. Loschner, Overview of the Ion Projection Litho graphy European MEDEA and International Program, Proc. SPIE 3997, 19 32 (2000). 

Figure 2.10 Micro-grafting using atmospheric pressure plasma. (A) Activation of a fluoropolymer foil throi h a silicon stencil mask using cm atmospheric helium plasma jet. (B) After grafting of 4 VP anti reaction with iotio-methane to form a strong polyelectrolyte, distinct differences in surface chemistry are evident from differences in wetting in water vapor. (C) After immersion in water, droplets remain only in the grafted areas.

One idea to create nanostructured device layers is to use the natural processes of self-assembly to position organic and inorganic molecules from the bottom-up (Feynman, 1959). One particular approach that has received a considerable amount of attention is the use of block copolymers as a patterning material because of their inherent ability to form periodic nanostructures in the mesoscopic (10-50 nm) length scale, coupled to the facility of one of the polymers to be selectively degraded to create nanoporous thin films. These nanoporous films could act like a stencil mask for subsequent etching steps into the underlying substrate. This topic has attracted much attention and inspired several excellent reviews (Fasolka and... 

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