Temperature silicon processes

The low temperature ALD process for hafnium silicate films using HfCl2[N(SiMe3)2]2 and H2O was modified to improve the film properties by two different methods. With hydrogen peroxide, the silicon content in the film increased to Si/(Hf+Si)=0.2 at 2001 and the impurity levels decreased due to its strong oxidation effect. By introducing TBOS as an additional Si precursor, the silicon content in the film increased to Si/(Hf+Si)=0.5 at 200 °C and the hafiiium silicate films became fully oxidized with O/(Hf+Si)=2.0. 

The Role of Point Defects in Silicon Processing. The Balancing Act in Silicon Processing. Both silicon oxidation and the diffusion of impurities occur at high temperatures and involve point defects such as va-... 

PECVD of silicon nitride has been of commercial importance since 1976.1 The original motivation was to find a final passivation layer for an integrated circuit that would replace the doped silicon dioxide films then in use. The latter were not reliable enough to permit packaging of integrated circuits in plastic. Silicon nitride was recognized as a better final passivation film, but the only available technique for its deposition was the high-temperature thermal process. Since it had to cover an aluminum final metallization layer that would melt at 600°C, this clearly could not work. The solution was to use PECVD at 350° to 400°C. 

The detailed analysis of mid-temperature relaxation processes observed in porous silicon was provided recently by using a superposition of two Jonscher terms of the form 4 /Ff/to)1 2-1 [160], The results of our... 

Thus, the non-Debye dielectric behavior in silica glasses and PS is similar. These systems exhibit an intermediate temperature percolation process associated with the transfer of the electric excitations through the random structures of fractal paths. It was shown that at the mesoscale range the fractal dimension of the complex material morphology (Dr for porous glasses and porous silicon) coincides with the fractal dimension Dp of the path structure. This value can be obtained by fitting the experimental DCF to the stretched-exponential relaxation law (64). 

The susceptor materials used in high-temperature processing include zirconia, boron nitride, graphite, carbon black, sodium-beta alumina, zinc oxide, and silicon carbide. While each of these susceptor materials has relatively high dielectric losses at room temperature, silicon carbide is also refractory with a relatively good resistance to oxidation at temperatures up to roughly 1500°C.t ° ... 

U.S. 4728457 (1988) Fieler (Procter Gamble) Heated premixes (silicone) are added to a main mix (surfactants and suspending agents) at ambient temperature Improved process for making silicone-containing shampoos... 

SixNy is usually deposited by PECVD [40]. Due to temperature restrictions imposed by the steel substrate, the maximum deposition temperature is limited. A further limitation can result from layers that have been deposited before the SixNy. When Au is used as a contact material, the deposition temperature is limited to <280°C because Au diffuses at higher temperatures. PECVD processes for silicon nitride deposition at temperatures below 280 °C are well known and commercially available. However, the low deposition temperature leads to a higher hydrogen content, making the films mechanically and chemically less stable [40]. 

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. 

Si3N4 layers deposited by CVD are important in the fabrication of certain semiconductor devices. One area is in the so-called LOCOS (local oxidation of silicon) process. This method is used in both bipolar and metal oxide semiconductor (MOS) devices to isolate active device regions. The process works as follows A layer of Si3N4 is deposited on the silicon wafer by CVD either by reacting silane and ammonia at temperatures between 700 and 900°C... 

Fig. 6. Comparison of viscosity and molding temperature for processing various silicones.

Practical application of the vulcanization of silicone rubbers using UV light is opening up new areas of application for silicone elastomers, since UV vulcanization enables extremely rapid curing to take place at low temperatures. This process makes it possible to combine silicone elastomers with heat-sensitive plastics, components, chemicals or medicinal products, which would previously have led to the destruction of the material or product because of the high curing temperatures [128]. 

Silicone rubber is obtained from polydimethylsiloxane (PDMS) in two ways (1) a high-temperature vulcanization process using a crosslinking reaction in the presence of peroxides and at high temperatures and (2) a room-temperature vulcanization process by using a crosslinking reaction of linear silicones with functional groups in the presence of Pt-based catalysts [99],... 

Replication techniques are available for transforming complex silica shapes into the corresponding shapes of various polymers. Ihe process can also be extended in the opposite direction, by converting the silica into silicon. Specifically, a low-temperature reduction process has been developed to convert three-dimensional nanostructured silica micro-assemblies into microporous nanocrystalline silicon replicas. Such materials could be useful in a variety of applications, including sensors and biomedical devices. 

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