Silicon process flow

Fig. 35. Process flow for thin-film imaging lithography (a) bilayer process and (b) top surface imaging. The bilayer process shown here employs a positive-tone imaging layer. The TSI process illustrated refles on preferential silicon incorporation in the exposed regions of the imaging layer to give a...

Power recovery, 20 139-143 Power recovery expander, 22 731 Power recovery systems process flow in, 22 730-731 types of, 22 729-730 PowerSearch software, 28 244, 250 Power semiconductors silicon-based, 22 260-261 silicon carbide in, 22 539-540 Power station design, 20 757 Power supplies... 

Silicone membranes, flow through, 15 722— 723. See also Membrane processes Silicone monomers, synthesis of,... 

Fig. 8 Schematic representation of block copolymer nanolithography process, a Schematic cross-sectional view of a nanolithography template consisting of a uniform mono-layer of PB spherical microdomains on silicon nitride. PB wets the air and substrate interfaces, b Schematic of the processing flow when an ozonated copolymer film is used as a positive resist, which produces holes in silicon nitride, c Schematic of the processing flow when an osmium-stained copolymer film is used as a negative resist, which produces dots in silicon nitride, (taken from [44])...

Figure 23. Processing flow for 3-D electrode array fabrication using silicon micromachining with colloidal filling of the electrode material. The six steps are identified as the following (i) patterned photoresist (PR) on silicon substrate, (ii) PR removal after DRIB micromachining, (iii) insulate silicon mold by oxidation, (iv) colloidal electrode filling material centrifuged into the mold, (v) silver epoxy added to provide mechanical stability and electrical contact, (vi) the electrode flipped over and released from the mold by immersion in a TEAOH solution.

A second approach for fabricating electrode arrays has involved micromachining of silicon molds, which are filled with electrode material by colloidal processing methods. In contrast to G-MEMS, this fabrication approach is suitable for both anodes and cathodes, as one merely alters the composition of the powders. The process flow for electrode array fabrication is depicted in Figure 23. 

Figure 11.3 Process flow from silicon feedstock to wafers for the case of multicrystalline silicon.

A clean silicon surface is critical in the production of smaller and faster logic and memory devices. A typical process flow for advanced integrated circuits consists of 300 to 500 steps, 30% of them being wafer cleaning operations. Trace amounts of impurities such as Na+ ions, metals, and particles are especially detrimental in the reliability of flnished devices. This is the main reason why nonvolatile reactants (alkali, alkaline earth as well as any metal... 

Figure 12 Schematic process flow-chart for the CVD synthesis of regular arrays of oriented nanotubes on a porous silicon through catalyst patterning (a) SEM image of nanotube blocks synthesized on 250 tm by 250 pm catalyst pattern. The nanotubes are 80 pm long and oriented perpendicular to the substrate, (b) SEM image of nanotube towers synthesized on 38 pm by 38 pm catalyst pattern. The nanotubes are 130 pm long, and (c) side view of the nantube towers in (b). (Reprinted with permission from S. Fan, M.G. Chapfrne, N.R. Franklin, T.W. Tombler, A.M. Cassell, and H. Dai, Science, 1999, 283, 512. 1999 AAAS)...

In the discussion below we limit ourselves to pure metal gates although alternatives have been proposed such as a tungsten/poly-silicon stack [Wong and Saraswat201]. It is helpful to keep the process flow as depicted in figure 8.1 in mind. 

Fig. 5 Schematic process flow for making electronic-grade silicon.

In the following example a typical, but rather general silicon-based process flow is described in the sequence of the processing steps (Fig. 5.3.1 a-d). The result is a simple micromachined cantilever beam, which - as will be described - can be anchored to the surface in two different ways (Fig. 5.3.1 e-f). 

Fig. 5.3.1 a-d Cross sections of a silicon-based MEMS device at several stages during surface micromachining process flow... 

Silicone membrane flow-through diffusion cells (SMFT) sensitive to solvatochromatic processes... 

It provides a more direct approach for temperature and pressnre compensation than other presently-available mass flow sensors requiring measurement of temperature and pressure. For some gas mixtures of varying composition, mass flow is indicated accurately (e.g. CO2 and He) without calibration corrections. Because it can be fabricated by conventional thin film deposition and silicon processing techniques. It offers the possibility of lower cost and broader applications than present conunercially available gas flow sensors. 

Conventional Production Process. Figure 69 shows the overall process flow and mass balance of the old process in operation since mid-1976. Target products in addition to VCM are hydrogen chloride for silicon chemistry and 20% hydrochloric acid for internal site demand. The combined VCM process was nearly HCl balanced because the HCl flow exported to silicon chemistry was balanced by imported HCl from a chlorolysis process (tetrachloroethylene production plant). The amount of by-products was all in all 4.4 wt % related to VCM production. According to Jensen et al. [170], ca. 64% of these residues are heavy ends and EDC-VCM tars which were... 

Figure 71 depicts the overall process flow and mass balance of the new process built at the end of 1991. The new process became HCl unbalanced by crack HCl export to silicon chemistry after special purification [171] and simultaneous shutdown of the perchlorination process for economical and ecological reasons. All residues containing chloroorganic compounds are thermally treated under chlorine and heat recovery in the new HCl generation plant (Fig. 72) [172]. 

Cast steel is normally melted in electric arc furnaces (EAF) or in coreless induction furnaces (IF). Once melted, the liquid metal can be refined (i.e. removal of carbon, silicon, sulphur and or phosphorus) and deoxidised (i.e. reduction of metallic oxides), depending on the base material and the quality requirement of the finished product. Figure 2.3 gives process flow diagrams for the melting and metal treatment of cast steel in the different furnace types. 

Lab-on-a-Chip Devices for Chemical Analysis, Fig. 7 Process flow for the fabrication of integrated waveguides (a) silicon substrate with a three-layered waveguiding structure (b) mask for forming the (c)... 

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