Airgap (microelectronics)

Airgap is an invention in microelectronic fabrication by IBM.

Description

By insulating copper wires within a chip with vacuum holes, capacitance can be minimized enabling chips to work faster or draw less power. A vacuum is believed to be the ultimate insulator for what is known as wiring capacitance, which occurs when two adjacent wires on a chip draw electrical energy from one another, generating undesirable heat and slowing the speed at which data can move through a chip. IBM estimates that this technology alone can lead to 35% higher speeds in current flow or 15% lower power consumption.

Fabrication techniques

IBM researchers have figured out a way to manufacture these "airgaps" on a massive scale, using the self-assembly properties of certain polymers, and then combine this with regular CMOS manufacturing techniques, saving enormous resources since they don't have to retool the entire process. When making the chips the entire wafer is prepared with a polymer material that when removed at a later stage leaves trillion of holes, just 20 nanometers in diameter, evenly spaced. Even though the name suggests that the holes are filled with air, they are in fact filled with nothing, vacuum. IBM has already proven this technique in their labs, and is already deployed in their manufacturing plant in East Fishkill, New York where they have made prototype POWER6 processors using this technology. Full scale deployment is scheduled for IBM's 45 nm node in 2009...
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