Last year everyone was gaga over graphene, the one-atom-thick mat of carbon molecules that can stop bullets and make better beer, as well as being a new form of semiconductor. Now it’s silicene’s moment. It is described by scientists at the University of Texas as a silicon analog of graphene, and they have learned how to make transistors out of it.
This isn’t easy; silicene doesn’t exist in nature and it is unstable when exposed to air. Conventional transistors are built on layers of silicon that are cut into thin wafers. Assistant professor Deji Akinwande and his team deposited a vapor of silicon atoms on a block of crystalline silver and then protected this with a layer of alumina. They then scraped away the silver on the bottom to make contact with the silicene molecules and voila, it’s a transistor. Akinwande describes the breakthrough in a news release:
“Apart from introducing a new player in the playground of 2-D materials, silicene, with its close chemical affinity to silicon, suggests an opportunity in the road map of the semiconductor industry. The major breakthrough here is the efficient low-temperature manufacturing and fabrication of silicene devices for the first time.”
Silicon is the backbone of the industry, and chipmakers know how to work with it. But silicone had been reaching its technical limits, and some were saying that if progress was going to be made in making transistors smaller and faster as demanded by Moore’s law, (the prediction that the number of transistors in an integrated circuit will double every two years) “we will need to kick the silicon addiction and adopt a novel technology.” That's why other scientists are working with graphene and other thin matrices.
However it appears that, in fact, there might be life in the old dog yet, and silicon might continue to do the job, in this novel, silicene form.
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