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The story of course does not end there. Since the early 1980s, the pace of innovation in semiconductor technology has accelerated. Chips currently in production contain in excess of 1,000,000 transistors. Dynamic random access memory chips (DRAMS), which have set the pace of progress in the industry, have provided a fourfold increase in capacity every three years—even though each increase has required engineers and scientists to solve ever more complex problems, driving the technology to even greater heights.

The photolithographic process used to fabricate the vast majority of semiconductor chips is conceptually relatively simple. The manufacturer applies a layer of photoresist (a material that reacts to light and resists the action of certain chemical agents) to a wafer of material called a substrate. The photoresist is exposed with a predetermined pattern. After being "developed," portions of the photoresist are washed away, leaving the substrate exposed. The substrate is then treated with a chemical agent that may etch material away from the exposed part, deposit material on it, or permeate into it. The manufacturer removes the photoresist and then repeats the process for each of the multiple layers required to form the device.5

The photolithographic process just described has many applications beyond semiconductor chips. The substrate does not have to be silicon (or any semiconductor for that matter), and the product does not have to be electronic circuitry. Manufacturers can use photolithography with masks on a variety of substrate materials, such as glass, polycrystalline silicon, sapphire, ceramic material, superconducting material, magnetic domain material—the list goes on and on, and continues to grow.

Moreover, the resulting product does not have to be a "chip." It can be a flat-panel display, a miniature motor and gears, a thin-film recording head, or any one of a number of items that are not usually considered to be electronic circuitry. It is possible that within a few years, virtually every portion of computer hardware, from the display to the mass storage devices to the packaging for chips, will be fabricated by using some kind of masking process.

Each stage of the process, from preliminary design through fabrication, requires investment, skill, creativity, and just plain hard work. As the technology became increasingly important in the U.S. economy, additional legal protection at some stage of the process appeared to be necessary to protect this investment if innovation was to flourish.6 Beginning in the late

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Alternatively. circuitry can be written directly on the surface of the substrate by using electron beams. This technique is not yet widely used commercially.

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I say "additional protection," because related aspects were already provided protection and continue to be—under the patent and copyright statutes, as well as trademark law and the laws of trade secrets and contracts.

For example, the patent statute protects any new and useful process, machine, manufacture or composition of matter, and any new, original and ornamental design for an article of manu



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