Diamond is an excellent conductor of heat and a poor conductor ofelectricity.
These properties would make diamond a useful material inthe manufacture of integrated-circuit chips, if it were possible toproduce paper-thin diamond films that could be used as electricalinsulators. Recently, researchers at the Hitachi Research Laboratory inJapan took some of the first steps toward bringing diamond films intomicroelectronics. The Japanese researchers, reporting their findings at lastmonth’s International Chemical Congress of Pacific Basin Societies(PAC CHEM ’84) held in Honolulu, found that microscopic diamondsare produced when microwaves irradiate a mixture of methane and hydrogengas.
This treatment forces the gases to decompose to create a plasma ofcharged particles. Over a period of hours, tiny diamonds, not more than30 micrometers in diameter, form on the surface of a solid support, suchas a silicon wafer, set inside the microwave chamber. The method, however, is far from ready for industrial application.The ideal conditions for producing diamonds have yet to be identified.Sometimes, for example, graphite and other types of carbon rather thandiamonds are deposited, and depending on the position of the solidsupport, occasionally no deposit forms and silicon is etched awayinstead.