Slashdot Mirror
Japan Developing Diamond-based Semiconductors
s spencer and others wrote in with submissions about Japan funding the development of diamond-based semiconductors to replace silicon chips. The main advantages of diamond include heat resistance and higher electrical resistance.
Actually diamonds are neither rare nor intrinsically valuable. The only reason that they cost so much at the jewelry store is because of the monopoly of debeers. They pretty much control all the diamonds in the world. if they wanted they could manufacture diamonds out of coal instead of mining them. It is not a lack of supply that makes them expensive but the fact that one company controls all the supply.
Diamonds are expensive for the same reason that Win2k costs $200 per seat. Actually, I prefer emeralds myself.
The GeekNights podcast is going strong. Listen!
They mean it can withstand higher voltages, not that it has higher electrical resistance. Silicon is an excellent insulator (extremely high electrical resistance) unless impurities (dopants) are added. That is key to the operation of a MOSFET.
There is (at least) one key advantage silicon has over diamond (or any semiconductor except Germanium). It has a self-repairing crystal lattice. When dopant atoms (phosphorous, arsenic, etc.) are injected into the bulk silicon wafer using ion implantation (diffusion not used in practice too much anymore) they cause structural damage to the crystal lattice which would hurt circuit performace. However, Silicon has this magical property that if you heat it up to the right temperature (several hundred degrees Celcius) the lattice begins to reorganize itself to incorporate the dopant atoms without damage. Tis process is called Annealing and it is one of the key reasons Silicon became the dominant semiconductor (the other was the availability of a good thermal oxide, SiO2).
Diamond does not have this desirable property, so a lot of research will have to go into maintaining the quality of the crystal lattice.
Here's some background on diamond films:
In July of this year, scientists in the United States reported that isotopically pure diamond films (containing 99.9% carbon-12 and not the 1% carbon-13 that is present in natural diamonds) had been grown. The pure films not only conducted hear 50% better than the best natural diamonds but also withstood damage by laser radiation ten times more effectively than natural diamond.
One could have the concept of combining functions: Glass that serves as a semiconductor, etc. Interesting.
I don't know if manufactured diamonds theaten the jewelry industry, but I doubt it. Although hundreds of almost-slaves labor in mines so deep it's scary, and the industry is full of creepy deals, people buy them, and the industry churns them out just the same.
mug
Yes Diamonds are better than Silicon but:
You still cannot get past some limmiting factors like speed of light and the absolute minnimum structure size.
What the Japanease are looking into will be very large chips. Diamonds are the only good way to get a good yeilds of these. But still when you have a 10x10mm 100 GHz chip it takes several clock cycles to get some information from one side of the chip to the other.
Normal design methodologies will no longer work in the near future just like they are starting to get difficult now. (Moore's Law slowing down)
Mouse powered Chips, Open source Processors and Lego
if they wanted they could manufacture diamonds out of coal instead of mining them
Not just yet. Other companies have manufactured diamonds, but they get cloudy after a few years. When this gets solved, you'll hear about it.
"We returned the General to El Salvador, or maybe Guatemala, it's difficult to tell from 10,000 feet"
These chips will not be based on cut diamond wafers in the way today chips are based on cut silicon wafers because it's pretty much impossible to cut diamond. Rather they would be based on evaporated diamond films (like the SOI - Silicon On Insulator - technique).
The fact that diamond is more suitable at higher temperatures is due to it's large band-gap: 5.5 eV (Si has 1.1 eV). So even at high temperature diamond is an (very good) isolator (very pure Si is also an good isolator at room temperature but it gets a lot more conductive at higher temperatures due to its small band gap). This large band-gap is also the reason why diamond would be a candidate for UV LEDs or lasers (UV starts at about 3eV). OTOH, Silicon with 1.1eV is in the infrared. BTW, the 235nm radiation they mention in the article corresponds to ~5.2 eV.
The idea of using diamond as a semiconductor has been kicking around for years with quite a bit of research being done world wide.
Technology Research News has an article published in September that discusses this.
Among other things they mention that diamond's charge carrier mobility is three times better.
Diamond transistors could in theory deliver one watt of power at 100 gigahertz, or billion cycles per second, said Isberg. This is five times faster has been achieved using the semiconductor Gallium Arsenide.
Diamond-based electronics would also be better than existing semiconductor materials for high-temperature applications, said Isberg. Diamond conducts heat 15 times more efficiently than silicon, and therefore cools faster.
etc. etc.
www.bannination.com Two things float to the top he
- Diamonds, as used in jewelry, are artificially rare. That's right.. the rock on your engagement ring is only rare because DeBeers & friends keep millions and millions of diamonds locked up in vaults. This is not conspiracy theory... it's a verifiable fact.
- The average cost of diamond, if all diamonds available were in circulation, instead of in vaults, would be about $1.50 per ct.
- Small diamonds, the kind used in diamond saws, industry, etcetera, are NOT expensive, like your engagement ring. Small diamonds are common and cheap, because they have no real jewelry market. Diamond impregnated stones and blades cost more because it costs more to manufacture them.. not because of the diamond.
- Good luck convincing your girl of ANY of this. You still have to buy that rock. Get over it..
"Until the late nineteenth century, diamonds were found only in a few riverbeds in India and in the jungles of Brazil, and the entire world production of gem diamonds amounted to a few pounds a year. In 1870, however, huge diamond mines were discovered near the Orange River, in South Africa, where diamonds were soon being scooped out by the ton. Suddenly, the market was deluged with diamonds. The British financiers who had organized the South African mines quickly realized that their investment was endangered; diamonds had little intrinsic value -- and their price depended almost entirely on their scarcity. The financiers feared that when new mines were developed in South Africa, diamonds would become at best only semiprecious gems."
Full article at The Atlantic
Diamonds are no longer rare, and are only worth anything for the same reason cabbage patch dolls once were: artificial scarcity.
pentium iii=mitsubishi?
For those who don't get it... mitsubishi means three diamonds in japanese.
Artificial diamonds most certaintly do not "look wrong".
According to the NOVA program "Diamond Deception" originally broadcast on 2/01/2000, "These synthetic diamonds are such good copies of the real thing that they not only have the identical atomic structure but can even replicate their flaws."