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Billions of Transistors on a Single Chip
cgi-bin writes, "IBM has reportedly developed technology to create "tens of billions" of transistors on a single chip. Intel's pentiums only have 27 million or so. The technique uses electron beams instead of the traditional optical lithography. "
Here's an advantage: System on a chip. How does a chip with a processor (maybe 2 or 4), large full speed cache, memory controller, PCI bridge, maybe 256MB (1GB? who knows?) of RAM, ethernet controller, etc., all on one chip sound? Sounds pretty good to me. Get memory latency down to like 1-1-1 and blazing i/o performance. You would make the motherboard extremely small and save a massive amount of space. Since the memory controller and PCI bridge ar on the Processor itself, the pin out can be kept under 400 pins. With enough memory on chip, who would need memory slots? This is the future IMHO.
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Don't lead me into temptation... I can find it myself.
This sounds to me like it's electron beam lithography, but not SCANNING electron beam lithography.
Electric fields can be used as lenses to focus electron beams, forming images of a stencil, just as physical lenses can be used to focus photon beams.
On one hand there's a complication because electrons mutually-repell and also affect the field that forms the lens, so higher beam currents tend to distort things somewhat.
On the other hand, the lenses are formed by an electric field's natural curvature. So small-scale optical imperfections just don't occur in a good vacuum, while gross imperfections are easy dealt with by maintaining decent tolerances in the construction and excitation of the electrodes.
Of course they COULD have made a breakthrough in scanning electron beam technology, and be talking about writing every chip one at a time. But that doesn't square with either the claims of "billions of transistors" and those of "speeding up the processing".
Yes, they could get DENSITIES of billions of transistors. But writing them one at a time takes a while. And keeping the beam alligned across a large chip is a problem. (Though the latter can be solved to some extent by first laying out a set of location markers and using them in later steps to figure out where the beam actually is.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I can hear Carl now from his grave.... "And this chip is populated with billions and billions of transistors on a single chip, all interacting and dancing to a tune called ... COMPUTING!"
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DO NOT DISTURB THE SE
John Markoff has a somewhat more detailed article on PREVAIL here.
The good news:
The new chip has over ten billion transisters.
The bad news:
The new chip is over 1700 square feet.
Plans for a portable based on the new chip are being put on hold...
The cake is a pie
1. Inorder to get the resolutions required in the future, photon lithography would have to go to X-rays that have a high enough brightness (i.e. You need a syncrotron X-ray source on site). For EBL, you just need a large source filament.
2. Masks for X-rays would need to be the same size as the actual features because there is still not a good method to make images out of X-rays so they use a shadowing technique. Not the case for EBL. Electrons use magnetic lenses to focus and have been used and designed for years. This actually allows you to build the mask in seperate parts and have the electron beam deflection put it all together for you as if it was all together.
3. Stepper motors don't need to be quite as acurate on positioning. This is because you can put in a simple feedback unit that examines where you are projecting on the surface of the wafer and deflection coils can position the beam exactly. This means that you can do lithography while the wafer is still moving! You couldn't do this in your wildest dream with X-rays.
4. Electrons have a very small wave-length at the acceleration voltages used (on the order of picometers). However, the real limitation for EBL is not the wavelength by lens abberations (pick up a good optics book) as well as space-charge effects (this happens because you are using a charged particle and they repel each-other giving a bluring effect). Even with all of this, some predict that you could get resolutions "easily" to the 10nm scale in lithography. No, we can't do atom manipulation with this technique.
5. No this technique does not use a focused beam technique (similar to scanning transmission electron microscopy), but it uses a plane-wave electron beam so that you can expose large areas at once (similar to stardard transmission electron microscopy), allowing for higher through-put.
Probably the major disadvantage for EBL right now is that we need more sensitive resists. The brightness of the EBL is still low compared to UV photon lithography, but I know of several groups that have come a long way with this one.
As another side note to this, Lucent Tech. has an EBL system just about at proof of concept called SCAPEL. Hope this clears up a few of the wrong ideas and helps people understand what this is all about.