Silicon AGe

Ross I M 1997 The Foundation of the Silicon Age Phys. Today December, p 34... 

Materials and their development are fundamental to society. Major historical periods of society are ascribed to materials (e.g.. Stone Age, Bronze Age, Iron Age, Steel Age, Polymer Age, Silicon Age, and SUica Age). However, scientists will open the next societal frontiers not by understanding a particular material, but by optimizing the relative contributions afforded by a combination of different materials. 

One can replace the oxygen atoms by other atoms, for example, by silicon itself. This leads to pure silicon, which cannot be neglected in the field of microelectronics. The significance of very pure grade silicon is so important for the entire electronic industry, especially for computers, etc. that we could say we are living in a "Silicon Age" in comparison to the "Ceramic Age or the "Bronze Age" of the past. 

At the request of Brattain, Pierce39 coined the name "transistor," an abbreviation of the neologism "transfer resistor." Later, Teal40 and Sparks41 made the first Ge BJT at Bell Labs in 1950, and Teal made the first Si BJT at Texas Instruments in 1954 [22], ushering in the "silicon age."... 

I.M. Ross, The foundation of the silicon age, Phys. Today, 1997 (December issue), 34. 

Contemporary culture is sometimes described as plastic, a somewhat critical reference to the pervasive use of polymeric materials in modern life. Others suggest that the current era is rightfully called the Silicon Age, in honor of the far-ranging impacts of modern electronics based on silicon technology. In any case, modern products, such as automobiles, contain a full spectrum of materials, from the traditional to the advanced. 

Torchinskaya TV, Korsunskaya NE, Khomenkova LYu, Shenkman MK, Batan NP, Misiuk A, Surma B (1997) Complex studies of porous silicon aging phenomena. In Proceeding of international semiconductor conference, IEEE, Sinaia, Romania, pp 173-176... 

Industrial hygiene began life in the metals trade. Mining and smelting of metals were the backbone of technological and industrial growth. Indeed, whole eras of human development are associated with the increasing sophistication with which humankind has worked with metals the copper age was succeeded by the bronze age that was in turn succeeded by the iron age. We are embarked on a new age characterized by new materials that define our civilization it may eventually be known as the silicon age. 

Materials have played such a critical role in the evolution of technology throughout the history of man that historical epochs, such as the Stone Age, the Bronze Age, the Iron Age, and the Silicon Age have been named for the materials available to mankind at the time. 

Hyperpure silicon can be doped with boron, gallium, phosphorus, or arsenic to produce silicon for use in transistors, solar cells, rectifiers, and other solid-state devices which are used extensively in the electronics and space-age industries. 

Modifications to Precipitates. Silicon is sometimes added to Al—Cu—Mg alloys to help nucleate S precipitates without the need for cold work prior to the elevated temperature aging treatments. Additions of elements such as tin [7440-31-5] Sn, cadmium [7440-43-9] Cd, and indium [7440-74-6] In, to Al—Cu alloys serve a similar purpose for 9 precipitates. Copper is often added to Al—Mg—Si alloys in the range of about 0.25% to 1.0% Cu to modify the metastable precursor to Mg2Si. The copper additions provide a substantial strength increase. When the copper addition is high, the quaternary Al CuMg Si Q-phase must be considered and dissolved during solution heat treatment. 

SiHcone elastomers possess outstanding resistance to heat aging. The Si—O—Si backbone imparts resistance to oxygen, o2one, uv, and to some polar fluids. However, the strength of these elastomers is usually just adequate. They have low abrasion resistance and tear strength (see Silicon compounds, silicones). 

Copper—chromium and copper—nickel—silicon—chromium alloys are also precipitation hardenable. The precipitates are nickel sdicides, chromium silicides, and elemental chromium. If conductivity is critical, the chromium—silicon ratio should be held at 10 1 so that appreciable amounts of either element are not left in soHd solution in the copper after aging. Lithium can be used as a deoxidizer in copper alloys when conductivity is important. For a discussion of the principle of age- or precipitation-hardening copper alloys, see Copperalloys,wrought copperalloys. 

Figure 29.5. Effect of aging at 250°C on the power factor of silicone-bonded, glass-cloth laminates.

Whilst exhibiting the excellent low-temperature flexibility (with a Tg of about -80°C) and very good heat resistance (up to 200°C) typical of a silicone rubber, the fluorosilicones also exhibit good aliphatic oil resistance and excellent aging resistance. However, for some applications they have recently encountered a challenge from the polyphosphazenes (see Section 13.10). 

A detailed account of the steps that led to the first transistor, and the steps soon afterwards to improve and miniaturise the device, and to shift from germanium to silicon, would take too much space in this chapter, and the reader must be referred to Riordan and Hoddeson s systematic and rivetting account, though space will be found for a brief account of the subsequent birth of the integrated circuit, the vector of the information age. But before this, some remarks are in order about the crucial interplay of physics and metallurgy in the run-up to the transistor. 

Fig. 7. Voigt model analysis of (a) lateral contact stiffness and (b) the response time, t, for a silicon nitride tip vs. poly(vinylethylene) as a function of frequency and polymer aging times. Reprinted with permission from ref [71].

Hermetically sealed electrical devices must be verified by a testing laboratory to meet mechanical abuse and to withstand aging and exposure to expected chemicals. Devices potted with common silicones and similar materials by an end user or even a manufacturer, without testing, and devices merely provided with O-rings seldom meet acceptable criteria. Normally, hermetically sealed devices must be sealed through metal-to-metal or glass-to-metal fusion. Many electrical relays, switches, and sensors are available as hermetically sealed devices for common oil and gas producing facility applications. Hermetically sealed devices are often desirable to protect electrical contacts from exposure to salt air and other contaminants. 

Silica (Si02) and silicates have been intimately connected with the evolution of mankind from prehistoric times the names derive from the Latin silex, gen. silicis, flint, and serve as a reminder of the simple tools developed in paleolithic times (. i00000 years ago) and the shaped flint knives and arrowheads of the neolithic age which began some 20 000 years ago. The name of the element, silicon, was proposed by Thomas Thomson in... 

E. Case V Predicting Crosslink Density Changes in Silicone Elastomers Due to Aging... 

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