ICs (Integrated Circuits) are used for many different things, including personal computers. "LSI (Large-scale Integration)" circuits, which have a higher level of density, are common today. A few thousands to a few tens of thousands of transistors are implanted in a 5-millimeter-square LSI circuit, and they are connected to each other horizontally and vertically with lines as thin as 1 micrometer (1/1000 millimeter).
If invisible dust specks, even those as small as 1 micrometer, were to fall onto the wiring, they would short out the circuits and the IC would be destroyed. Electric appliances and personal computers would shut down. This is why semiconductor manufacturers make ICs in a "clean room" where there is almost no dirt or dust. However, in case there happens to be dust on ICs for some reason, it is necessary to figure out the cause.
An X-ray micro analyzer plays an important role in such situations. This device analyzes the constituents of invisible dust particles that are as small as 1 micrometer, by magnifying a particle by a few tens of thousands times its size using an electron microscope. Substances consist of various elements, and each element has unique attributes. Every element emits X-rays when exposed to an electric beam from an electron microscope for the purpose of magnification and observation, and all are different depending on the element in question. Using this attribute, it is possible to tell the constituents of a particular type of dust by analyzing the energy output of X-rays. Manufacturers and others can learn where dust came from by studying what makes it up, and then can eventually determine its cause.
A 0.5-1 micrometer dust particle on a 5-millimeter-square IC is analogous to a ladybug somewhere in the large Tokyo Dome stadium. The X-ray micro analyzer has the ability to find such a "ladybug in the Tokyo Dome," and even to analyze what it is made of. This device is widely used in semiconductor manufacturing, new material industries, the chemical industry, and many other sectors.
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