Research Discovery Could Revolutionize Semiconductor Manufacturing 64
New submitter arobatino writes "A new method of manufacturing semiconductors which eliminates the substrate (in other words, no wafer) could be much faster and cheaper. From the article: 'Instead of starting from a silicon wafer or other substrate, as is usual today, researchers have made it possible for the structures to grow from freely suspended nanoparticles of gold in a flowing gas. "The basic idea was to let nanoparticles of gold serve as a substrate from which the semiconductors grow. This means that the accepted concepts really were turned upside down!" Since then, the technology has been refined, patents have been obtained and further studies have been conducted. In the article in Nature, the researchers show how the growth can be controlled using temperature, time and the size of the gold nanoparticles.'"
expect to be able to ... p-n diodes (Score:5, Informative)
That is like 1950's technology levels. A long time before they can make million gate devices.
There are many many problems associated with replicating sub-nanometer scale patterns on a ground flat substrate. If they don't have a planaer substrate they are going to have lots of problems creating the required imaging patterns. Note that at the current scales you can't print a | object as a simple | you have to make it look like an I, essentially doing what is called dog-boneing because of eteching and diffraction effects. And multiple parallel lines have big problems with diffraction effects.
So currently it seems without a substrate then can make ...... a single p- or n- type semiconuctor material that is unsuitable for anything else.
gold is a contaminant (Score:2, Informative)
gold is a very severe contaminant for silicon, and many other semiconductors.
It sits energy wise in the center of the band gap and kills mobility with traps.
Gold is rigorously excluded from silicon FABS, not even let in the same room.
Re:expect to be able to ... p-n diodes (Score:0, Informative)
Somewhat misleading headline (Score:5, Informative)
Re:Is gold is cheaper than silicon? (Score:1, Informative)
Yes, it is.
The amount of gold this process would use (if it actualy created a circuit) is incredibly low (much less than the amount of silicon in a current chip), and gold is an order of magnitude cheaper than purified silicon.
Re:Is gold is cheaper than silicon? (Score:5, Informative)
a 200mm wafer is 0.775mm thick. A quick google says this is about $1200. I'm not sure when this was, but the price keeps dropping.
If you made a 200mm x 0.775mm gold disk, it would weigh 470g. The price of gold is currently $55.40/g. That's a $26,000 hunk of metal, 20x the price of silicon wafer.
Going on the 'order of magnitude cheaper' If a 200mm wafer cost $260,000 for 31,415mm3 of surface area it would be impossible to get more than 60 xeon 8800's (513mm2) (much less, since the die in a CPU is square so the edges re unusable and there is probably a need for cutting lines, not to mention yield), The raw die alone would cost $4,333.
Components? (Score:4, Informative)
That seems much more feasible than what is implied by the title of this post.
Re:gold is a contaminant (Score:4, Informative)
Gold is rigorously excluded from silicon FABS, not even let in the same room.
Actually gold is the highest quality metal for bondwires or top-level bondpad metalization. You're right that gold is a severe contaminant, but it is also a very good conductor, and is easy to work with. It most certainly used extensively in fabs, although care is taken not to contaminate. I used gold interconnect in a chip just a few months ago, in a very up-to-date process.
The vast majority of chemicals used in a fab will severely degrade circuits if they are introduced into the process at the wrong time or in the wrong way. Gold is not a special exception here.
Re:The first rule of semiconductor manufacture is. (Score:5, Informative)
There will be at least one time that some other process came from nowhere and beat silicon litography in nealy all aspects. (The laws of physics almost assure that.)
Not so sure about that. Lithography is one of the most highly developed technologies in the history of the world, and has gone far, far deeper than most people expected as early as the 1980s. Proposal after proposal has been made to replace lithography (e.g. e-beam, MBE, etc) but all have to relegated to niche status.
Semiconductor lithography itself is highly, highly leveraged from printing processes going back hundreds of years. With this much brain power and inertia behind it I would be really, really surprised if something beats it in "nearly all aspects". Some aspects, maybe, and lithography may finally hit a show-stopper, but there won't be an "oh my, what a breakthrough" type thing to replace it. I agree it has to be replaced to maintain Moore's law, but it is already beyond comprehension advanced.
Re:gold is a contaminant (Score:3, Informative)
Yep. Sometimes you want to introduce recombination centers to kill the lifetime. Nowadays they zap the wafer with radiation to do this.