IBM increases chip speed with vacuum spaces

IBM has developed a technique of creating vacuum spaces between copper wires in semiconductors which will provide increased speed, enhanced performance and reduced power consumption.

The ‘Airgap’ technique could increase chip performance by 35% and reduce power consumption by 15%. It will form part of IBM’s manufacturing process for the 32-nanometer generation of microprocessors.

Insulation is used in chips to inhibit unintended transmission and chatter between wires, and a vacuum provides the most efficient form of insulation possible.

The technique for inserting vacuum gaps in chips arose from research on self-assembling molecules, called diblock copolymers, conducted by IBM researcher Chuck Black.

A diblock copolymer comprises two types of molecule that would ordinarily repel each other. However by designing the molecules in a particular way and controlling their interaction, they create intricate patterns through chemical repulsion.

The Airgap technology involves creating copper wires on a chip and then depositing insulators between the wires. The diblock copolymer is then applied resulting in an evenly spaced matrix of dots, with each dot having a 20-nanometer diameter.

These dots are then chemically etched away and become holes.

Further etching removes the insulating material and the void is capped to create a vacuum.