Silicon processing technique

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. 

Because this sensor can be fabricated by conventional thin film deposition and silicon processing techniques, it offers the possibility of lower cost and broader applications than present commercially... 

Finally, silicon processing techniques have also been leveraged to make novel ion conducting membranes. Porous silicon can be readily created in a silicon substrate by an anodization process in HF. The result is a nanoporous structure with over 50 % porosity. By forming thick membranes of porous silicon (>40 pm) loaded with sulfonic acid, ionic conductivities similar to Nafion were attained (10-10 S/cm) [5]. 

Ein-Eh Y, Starosvetsky D (2003) Silicon texturing in alkaline media conducted under extreme negative potentials. Electrochem Sohd State Lett 6 C47-C50 G6mez H, Henriquez R, Schrebler R, Riveros G, Leinen D, Ramos-Barrado JR, Dalchiele EA (2004) A soft-solution electrochemical processing technique for preparing CdTe/n-Si(lOO) heterostructures. J Electroanal Chem 574 113-122... 

At present, defect-free silicon crystals have been achieved at only at diameters of 200 mm. Comparisons of crystal quality were made among three techniques a typical conventional Czrochralski crystal growth technique, a slow-cooled controlled reaction and the perfect silicon process. The quality levels achieved in D-defect levels of the material is... 

The next step is to produce nearly perfect single-crystal boules of silicon from the ultrapure polycrystalline silicon. Many techniques have been developed to accomplish this, and they all rely on a similar set of concepts that describe the transport process, thermodynamically controlled solubility, and kinetics [8]. Three important methods are the vertical Bridgman-Stockbarger, Czochralski, and floating zone processes, fully described in Fundamentals of Crystal Growth by Rosenberger [9]. 

Less-conventional processing techniques are also used to make ceramic matrix composites. Siliconized silicon carbide, for example, is made by liquid infiltration.16,17 A compact of SiC particles is formed and then presintered, or reaction bonded. Liquid silicon is then infiltrated into the structure. Many different microstructures of siliconized silicon carbide can be made in this manner. The volume fraction of SiC particles can be as high as 90vol.%. Bimodal structures have also been made by this technique. These materials are used for radiant heaters and heat exchangers.17,19... 

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