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Stanford Breakthrough Could Make Better Chips Cheaper

Posted by Soulskill on from the encheapificating-the-expensive-part dept.

angry tapir writes: Researchers at Stanford University have come up with a new way to make chips and solar panels using gallium arsenide, a semiconductor that beats silicon in several important areas but is typically too expensive for widespread use. "[I]t can cost about $5,000 to make a wafer of gallium arsenide 8 inches in diameter, versus $5 for a silicon wafer, according to Aneesh Nainani, who teaches semiconductor manufacturing at Stanford. The new Stanford process (abstract) seeks to lessen this thousand-to-one cost differential by reusing that $5,000 wafer. Today the working electronic circuits in a gallium arsenide device are grown on top of this wafer. Manufacturers make this circuitry layer by flowing gaseous gallium arsenide and other materials across the wafer surface. This material condenses into thin layer of circuitry atop the wafer. In this scenario, the wafer is only a backing. The thin layer of circuitry on top of this costly platter contains all of the electronics."

4 of 56 comments (clear)

  1. The Wankel Engine of the Semiconductor Industry by Etherwalk · · Score: 4, Interesting

    One of the very first papers I read for a VLSI design course had one of the weirdest final sentences I have ever heard, from a geeky see-my-smarts cross between physics and car geeks. As I recall, it was something like this:

    "And then, of course, there is the problem of gallium arsenide, which is the Wankel Engine of the semiconductor industry."

    To which the class (a bunch of undergrads wading into the delightful bliss and head-scratching geekery of academic journals for the first time) collectively and perplexedly said "WTF?"

    1. Re:The Wankel Engine of the Semiconductor Industry by ShanghaiBill · · Score: 4, Interesting

      I guess that would be because like Wankel engines, gallium arsenide is a better solution to the problem at hand, but won't ever get a break because the existing design is entrenched...

      No, entrenched designs are not what is holding back either GaAs or Wankel engines. Although both are, in theory, elegant solutions, in practice, both have major flaws, and just don't work very well. Both have been subjected to decades of research that have not found solutions to the problems. I don't expect this research to change things much. GaAs will just go from ridiculously impractical, to very impractical. I expect to have a graphene CPU before I have a GaAs CPU.

  2. Re:No cheaper, just recyclable. by itzly · · Score: 3, Interesting

    No, they are making a wafer, building chips on top, remove thin top layer to sell the chips, and reuse the bottom part.

  3. the presentation is BS by serbanp · · Score: 5, Interesting

    The article follows the youtube presentation and the summary is, for once, accurate (i.e. does not introduce new errors).

    The trouble is that the presentation is utter BS. The GaAs devices are NEVER made out of a solid GaAs wafer; the process starts with a plain silicon wafer, on which GaAs is grown epitaxially. The secret sauce is, and always has been, how to minimize the defect density at the Si/GaAs interface.

    Such a wafer is more expensive than the plain Si one, but not 1000x more! Oh, and every purchaser would kill to get $5 8" wafers...

    Since the Stanford guys are no dummies, I guess that the announcement was deliberately made to sound ridiculous. For what purpose? Time will tell.