Word: silicones
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Dates: during 1970-1979
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...sell out to larger firms. That could endanger the vitality of the valley. Explains Sanders: "This industry has amoeba-like qualities. It doesn't combine very well. It splits." That characteristic is the essence of competition, and no industry has better shown its benefits than the denizens of Silicon Valley...
Pondering the difficulty, Hoff was suddenly struck by a novel idea. Why not place most of the calculator's arithmetic and logic circuitry on one chip of silicon, leaving mainly input-output and programming units on separate chips? It was a daring conceptual move. After wrestling with the design, Hoff and his associates at Intel finally concentrated nearly all the elements of a central processing unit (CPU), the computer's electronic heart and soul, on a single silicon chip...
...generated tremendous quantities of heat, and frequently burned out. In an industry striving for miniaturization, the transistors, too, soon began to shrink. By 1960, engineers had devised photolithographic and other processes (see box) that enabled them to crowd many transistors as well as other electronic components onto a tiny silicon square...
Some 250 chips are made from one razor-thin wafer of precisely polished silicon about 3 in. in diameter. These wafers, in turn, are sliced from cylinders of extremely pure (99.9%) crystalline silicon, grown somewhat like rock candy. Why silicon? Because it can be either electrically conducting or nonconducting, depending on the impurities added to it. Thus one small area of a chip can be "doped" (as scientists say) with impurities that give it a deficiency of electrons-making it a so-called p (or electrically positive) zone, while an adjacent area gets a surplus of electrons to create...
First, racks of wafers are placed in long cylindrical ovens filled with extremely hot (about 2,000° F.) oxygen-containing gas or steam. In effect, the wafers are rusted-covered by a thin, electrically insulating layer of silicon dioxide that prevents short-circuiting. Then the wafers are coated with still another substance: the resist, a photographic-type emulsion sensitive only to ultraviolet (UV) light. (To prevent accidental exposure, clean rooms are generally bathed in UV-less yellow light.) Next, a tiny mask, scaled down photographically from a large drawing and imprinted with hundreds of identical patterns of one layer...