Word: wafers
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...devices that use the sun's rays to heat rooftop water panels, which in turn heat swimming pools and home water systems. But the exciting side of the industry that is attracting the larger companies is photovoltaics?the direct conversion of sunlight into electricity. The theory is simple. A wafer-thin, 3-in. to 4-in. plate or "cell' that is sliced from a chemically treated silicon crystal will give off direct-current electricity when exposed to light. The amount that comes from each cell is minute, but many cells can be wired together in rooftop units to provide...
...plot is wafer thin. Henry Williams (Charles Repole) is slight in stature but huge in hypochondria, and so full of pills that when he sneezes "people around me get cured." By happenstance, Henry extricates Sally Morgan, a coy maiden winsomely played by Beth Austin, from the maritally-minded clutches of Sheriff Bob (J. Kevin Scannell), a sage brush Keystone Kop. Sally's true love is Hiawatha, or rather, Wanenis (Franc Luz), a noble North American savage from red-blooded Dartmouth. She gets him, and after a number of featherbrained misadventures, Henry finds perfect health and pneumatic bliss...
Monolithic Memories Corp. has a standing order for wafer sorters and probe-card repair technicians; meanwhile, the company is turning down orders for lack of workers. Synerteck needs ion implanters, who manipulate control panels to change the electrical properties of silicon. Fairchild Camera and Hewlett-Packard both have hundreds of positions available that cut across every level of skill. Avantek has an eye out for janitors interested in profit sharing...
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...
Back in the ovens, the wafers are baked again in an atmosphere of gases loaded with "dopants." Like oil stains in a concrete driveway, these impurities soak into the underlying silicon. Since chips usually contain as many as ten layers, all these steps-"rusting," photomasking, etching, baking, etc.-must be repeated for each layer. Then the entire wafer is coated with an aluminum conductor, which also must be masked, etched and bathed in acid. Finally, an eagle-eyed computerized probe scans the wafer for defective circuitry and marks the bad chips in red. The wafer is then separated...