Photo-masking

Use photo mask and illuminate (mask reproduces photographic pattern of desired circuit geometry)... 

In 2009, Ayela and coworkers proposed the large scale fabrication of MIP microbiochips using an optimized photo-masking process [75]. A resolution of... 

To follow this approach subsystem layout and functions as well as microfabrication processes have to be selected, which are apt to generate and integrate the various subsystems of a mass spectrometer into one substrate in one batch process, i.e., all the components are defined in their geometry and orientation among each on one photo mask, which is then transferred into features in the substrate. Thus, submicron accuracy of device features and their orientation and adjustment can reproduc-ibly be guaranteed, i.e., many identical devices can be fabricated simultaneously in one run. This, however, also means that all the subsystems are fabricated in the same material within a narrow range of the necessarily different dimensions. 

Applied substrates require homogeneous and planar surfaces. Planar supports allow accurate scanning and imaging, which rely on a uniform detection distance between the microarray surface and the optical device. Planar solid support materials tend to be impermeable to liquids, allowing for a small feature size and keeping the hybridization volume to a minimum. Flat substrates are amenable to automated manufacture, providing an accurate distance from photo masks, pins, ink-jet nozzles and other manufacturing implements. The flatness affords automation, an increased precision in manufacture, and detection and impermeability. Table 1 shows frequently used support materials... 

Figure 10-2 Two glass photo masks approx 125x 125 mm) showing patterns for multiple PCR devices to be fabricated in silicon.

A, Silicon wafer (hashed) with etch mask (white), B, Application of photo resist (black) onto etch mask. C, Exposure of photo resist through photo mask. D, Positive and negative photo resist after development of resist. E, Removal of etch mask. 

F, Removal of photo resist, leaving either the pattern present in the photo mask or its opposite patterned into the etch mask. 

We have found that poly(l-butene sulfone) with p-pyridine N-oxide as a sensitizer yielded positive tone polymer patterns in thermal development after UV light exposure through a conventional photo-mask with a cut-off wavelength of 300 nm. Poly(l-butene sulfone) was mixed with... 

Particle Ramoval (Semiconductor Process Fluids). The fluids that come in contact with photo masks and wafers during integrated circuit (IC) production are often contaminated with particles which, if not eliminated, can cause defects and reduce production yields. 

Photo mask with etched test pattern. 

In the production of dials on glass, enormous progress was achieved by replacing old techniques such as chemical etching and mechanical scratching by thin film deposition. Depending on the size of scale, mechanical masks or photo masks are used. The deposited metal is for the most part chromium. Figure 40a shows a comparison of the quality of scales produces by different techniques. 

See, for example, Chromium etchants applications notes, Cyanetek Corp., Fremont, CA [cited in H.J. Levinson, Principles of Lithography, 2nd ed., p. 261, SPIE Press, Bellingham, WA (2005)]. B.J. Curtis, H.R. Brunner, andM. Ebnoether, Plasma processing of thin chromium films for photo masks, J. Electrochem. Soc. 130(11), 2242 2249 (1983). 

Figure 2. Mechanism of photosensitized polymerization of pyrrole and optical microscope photographs of (A) ptdypyrrole synthesized on Nafion film by photosensitized polymerization (B) photo mask used for photoinadiation (width of line = 10 im).

Fig. 5.9 (a) Transmittance response of copolymer MACB-CNB6 during irradiation with polarized light (A to B) and unpolarized light (C to D) at 106°C. (b) One-year-old image stored in the liquid-crystal copolymer. The film was covered with a photo mask during irradiation with polarized light at A=366 nm (2.8 mWcm" ) and 106°C. Adapted from Wu et al. [45] with permission from Elsevier. 

Andou et al. investigated the consecutive photo-induced GASP of MMA and St to build up a finely designed deposition of 2D and 3D patterns on solid surfaces (Figure 4.4) [14, 15]. Under UV-irradiation through a stripe-patterned photo mask on a Si-wafer or Au-plate surface, the photo-induced GASP resulted in the... 

Minimum gap sizes and electrode widths were in the order of 0.2 and 0.5 mm, respectively. Using photo-masks, coplanar microscale Ptand Au electrode structures were fabricated by sputtering [77]. Although the cells delivered very low OCVs, the smallest inter-electrode gaps (5 am) and electrode widths (15 am) reported so far were realized by this fabrication technique. 

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