Copper Interconnect Architecture

Every chip has a base layer of transistors, with layers of wiring stacked above to connect the transistors to each other and, ultimately, to the rest of the computer. The transistors at the first level of a chip are a complex construction of silicon, metal, and impurities precisely located to create the millions of minuscule on-or-off switches that make up the brains of a microprocessor. Breakthroughs in chip technology have most often been advances in transistor-making. As scientists kept making smaller, faster transistors and packing them closer together, the interconnect started to present problems.

Copper

Aluminium had long been the conductor of choice, but by the mid-1990s it was clear that it would soon reach the technological and physical limits of existing technology. Pushing electrons through smaller and smaller conduits becomes harder to do – aluminium just isn’t fast enough at these new, smaller sizes. Scientists had seen this problem coming for years and sought to find a way to replace aluminium with one of the three metals that conduct electricity better: copper, silver, or gold. However, after many years of trying, no one had succeeded in making a marketable copper chip.

All this changed in September 1998, when IBM used its revolutionary new copper interconnect technology to produce a chip which used copper wires, rather than the traditional aluminium interconnects, to link transistors. It was immediately apparent that this seemingly minor change would have significant repercussions for future processor designs. Copper interconnects promised the ability to shrink die sizes and reduce power consumption, while allowing faster CPU speeds from the same basic design.

IBM has historically been renown for its lead in process technology, but has often failed to capitalise on it commercially. This time it has implemented the technology rapidly, first announcing the 0.18-micron CMOS 7SF Damascus process at the end of 1997. Subsequent development was by a four-company alliance which included fabrication equipment manufacturer Novellus Systems and, in 1999 IBM offered the 7SF process to third parties as part of its silicon foundry services.

One of the problems which had thwarted previous attempts to use copper for electrical connections was its tendency to diffuse into the silicon dioxide substrate used in chips – rendering the chip useless. The secret of IBM’s new technology is a thin barrier layer, usually made from refractory titanium or tungsten nitride. This is applied after the photolithographic etching of the channels in the substrate. A microscopic seed layer of copper is deposited on top of this to enable the subsequent copper layer, deposited over the whole chip by electroplating, to bond. Chemical polishing removes surplus copper.

GD Star Rating
loading...
GD Star Rating
loading...
Copper Interconnect Architecture, 10.0 out of 10 based on 2 ratings

Latest Articles

UTP

UTP Definition: Unshielded Twisted-Pair: a four-pair wire medium used in a variety of networks. UTP does not require the fixed spacing between connections that is necessary with coaxial-type connections. See also STP. … [Read more...]

OSD Data Storage Technology

Optical Super Density (OSD) technology's design goals were to develop a high capacity (40GB or more) removable MO drive which retained the ruggedness and reliability offered by today's ISO-standard MO solutions, achieve data transfer rates … [Read more...]

Diskeeper review

Disk Keeper 2011 Pro Premier Review

PROS: Disk Keeper 2011 Pro Premier Review for servers and high performance personal computers. CONS: The results of the Disk Keeper 2011 Pro Premier Review. OVERVIEW: Disk Keeper 2011 Pro Premier Review defragments thoroughly and does an excellent job at handling your hard … [Read more...]

Virus Guides

MySearchPage-net

MySearchPage.net virus Info and Control

MySearchPage.net virus is now popular not because it is one of today’s revolutionary search engine varieties but because this is one browser people get scared from whenever they see this running on their computers. This fake and nasty search engine is actually a browser hijacker so what it does is … [Read more...]

Comments

    • Anonymous says

      Provide a source so we can. From all research done this article is accurate. “All this changed in September 1998, when IBM used its revolutionary new copper interconnect technology to produce a chip which used copper wires”. IBM was the first to use copper interconnect technology to produce a chip that used copper wires.

      GD Star Rating
      loading...
      GD Star Rating
      loading...

Leave a Reply

Your email address will not be published. Required fields are marked *