Self-alignment

Step 8. The -type source and drain regions are created by As ion implantation. The As can penetrate the thin gate oxide, but not the thick field oxide or the polysihcon gate. The formation of the source and gate does not require a separate resist pattern, thus this technique is called self-aligning. 

To achieve the lowest possible delay a bipolar switching transistor developed by IBM minimizes parasitic resistances and capacitances. It consists of self-aligned emitter and base contacts, a thin intrinsic base with an optimized collector doping profile, and deep-trench isolation (36). Devices must be isolated from each other to prevent unwanted interactions in integrated circuits. While p—n junctions can be used for isolation, IBM s approach etches deep trenches in the siUcon wafer which are filled with Si02 to provide electrical insulation. 

Figure 19.4 Rear view of a bulk oil circuit breaker assembly showing single-break contacts, self aligning cluster Isolating contacts, terminal bushing and arc control pots (Courtesy ...

Design parts to be self-aligning and self-loeating... 

Deep groove Angular contact ball bearing Four-point Self-aligning... 

The labyrinth sleeve ean be flexibly mounted to permit radial motion for self-aligning effeets. In praetiee, a radial elearanee of under 0.008 is diffieult to aehieve, exeept with very small high-preeision maehines. On larger turbines, elearanees of O.Ol5-0.02 are generally used. During maehine eon-struetion, it is important to measure and reeord these elearanees beeause meehanieal seizure or loss in aerodynamie effieieney ean often be traeed to ineorreet labyrinth seal elearanees. 

Self-aligning ball bearings supporting radial and thrust load where shaft and housing are subject to misalignment excellent rubber mixers, oil field drilling rigs, vertical pumps... 

Spherical High radial and moderate-to-heavy thrust loads, usually comes in double-row mounting that is inherently self-aligning. 

Figure 60.12 Double-row internal self-aligning bearing...

Spherical bearings are usually furnished in a doublerow mounting that is inherently self-aligning. Both rows of rollers have a common spherical outer raceway. The rollers are barrel-shaped with one end smaller to provide a small thrust to keep the rollers in contact with the center guide flange. 

Most pillow-block designs incorporate self-aligning bearing types and do not require the precision mountings utilized with other bearing installations. 

The salicide concept (self-aligned silicide) is now used extensively in MOSFET devices. It is based on TiSi2 and CoSi2, both of which are deposited by CVD.l k l The CVD reactions for the deposition of silicides are described in Ch. 12. 

FIGURE 26.28 Side force coefficient and self-aligning torque of a radial ply tire 175 R 14 on two wet road surfaces of different friction coefficient, at three slip angles and loads as function of the quantity c (Equation 26.17c) aU on log scales. The sohd hnes correspond to the brush model. (From Schallamach, A. and Grosch, K.A., Mechanics of Pneumatic Tires, S.K. Clark (ed.). The US Department of Transportation, National Highway Safety Administration, Washington DV.)... 

Hiranaka, K. Yamaguchi, T. Yanagisawa, S. 1984. Self-alignment processed amorphous-silicon ring oscillators. IEEE Elec. Dev. Lett. 7 224-224. 

Nanoparticles were prepared on the basis of our previous report. In brief, Co nanoparticles were synthesized via a high-temperature thermo-decomposition method.Three-, five-, and twelve-nanometer Co nanoparticles in dichlorobenzene (DCB) solutions were made and used to make self-aligned nanostructures (SAN) and SiNW. 

FIGURE 10.1. Apparatus used to grow silicon-based self-aligned nanostructures and nanowires. A quartz tube was placed in a high temperature furnace (shown here). Ar, H2 and CH4 selectively flowed through the tube. 

J. D. Carter, G. Cheng, and T. Guo, Growth of self-aligned crystalline cobalt siUcide nanostructures from Co nanoparticles, J. Phys. Chem. B 108, 6901-6904 (2004). 

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