Ultra-Thin Alternative To Silicon

An anonymous reader writes "There's good news in the search for the next generation of semiconductors. Researchers with the Lawrence Berkeley National Laboratory and UC Berkeley have successfully integrated ultra-thin layers of the semiconductor indium arsenide onto a silicon substrate to create a nanoscale transistor with excellent electronic properties (abstract). A member of the III–V family of semiconductors, indium arsenide offers several advantages as an alternative to silicon, including superior electron mobility and velocity, which makes it an outstanding candidate for future high-speed, low-power electronic devices."

Comments

Four words why this is useless.

[the_raptor]

Restriction of Hazardous Substances.

There are already a bunch of non-substitutable components that can't be used because of RoHS. Adding arsenic to make faster electronics is just not going to fly (it doesn't matter if current methods are just as toxic, everyone knows about Arsenic and RoHS is half PR). Researchers should be concentrating on making electronics less toxic so we don't keep poisoning African and Asian kids (working for electronics "recyclers") with last years iPhones.

Re:Four words why this is useless.

[bertok]

That's just under 3 micrograms of arsenic. According to our trusted interwebs source, wikipedia: "The acute minimal lethal dose of arsenic in adults is estimated to be 70 to 200 mg". In other words, each chip contains about 1/25,000th of the lethal dose, in a non-soluble form.

I'll think you'll be fine.

Re:Arsenic compounds

[dbIII]

I'd say a lot safer than that green wood you see in playground equipment that has been treated with an arsenic compound to stop termites from eating it (and that stuff has been tested a lot because some kid somewhere is going to chew it). If we are going to be irrationally scared of elements then Teflon would scare the crap out of everyone.
The answer as usual is how the stuff will behave with any bit of your body that it is likely to come in contact with and that decides what sort of hazard it is. For instance reactive stuff is an obvious hazard and things that will get into your lungs and never get out or break down another. This stuff is going to have very strong covalent bonds that stomach acid isn't going to touch.
Oddly enough someone at the University I was working at in 1998 made a very thin diode junction of a very similar material using chemical vapour deposition and he wasn't the first to do so. Making a thin layer of the stuff is relatively easy, making an isolated very tiny transistor is hard.

Re:Dumb Question

[Raptoer]

Put simply, the way a transistor works requires the use of semiconductors. It's a property other than resistance which the transistor requires. When not in a transistor, materials with a high conductivity are used.

Re:Why Bother?

[the_pooh_experience]

Because it is possible and demonstratable to grow InAs today. It is grown in bulk, single crystal material. Graphene, while making strides in the "manufacturable" direction, is still practically relegated to grad students shaving pencils with razors onto tape to get a single monolayer film.

Re:Arsenic compounds

[tom17]

Yes, and Arsenic. It's CCA (Chromated Copper Arsenate)

However, this is being phased out for Alkaline Copper Quaternary or Copper Azole. In the EU, CCA is no longer allowed for domestic or residential applications. It's also being used more in north america now too.

Re:Arsenic compounds

[Anonymous Coward]

It's both. Chromated Copper Arsenate.

Re:Arsenic compounds

[ChrisMaple]

As of about 4 years ago, the formulation for copper-based wood preservatives was changed to eliminate arsenic; the arsenic compounds becoming illegal for residential use in the United States. New compounds are copper azide and other copper-organics.