IBM has developed a new process called airgap that copies nature"s creation of seashells and snowflakes - it enables trillions of microscopic vacuum holes to be placed between the copper wire in chips to act as an insulator. This solves the problem of electrical energy leaking between wires, creating unwanted heat. IBM says the chips will run 35% faster and consume 15% less energy. The new chips will be initially put to work in IBM"s server machines - used by businesses and research groups - and the process will then be rolled out to the firm"s semiconductor partners.
The company has developed a method of controlling the interaction between self-assembling molecules, called diblock copolymers, to create the vacuum holes. While the self-assembled polymers were developed back in 2001, it is the first time anyone has been able to produce mass quantities and integrate them into a manufacturing process with high yields. The controlled interaction between the molecules creates a series of evenly-spaced dots - each one only 20-nanometres in diameter. Those dots are then etched away in a chemical process, forming holes, which are then capped to create a vacuum. The properties of a vacuum simply destroy the current use of silicon dioxide as an insulator.
"The big breakthrough is getting it into a manufacturing process and producing 300mm diameter wafers with the process working. This is never easy as the yields need to be near perfect for every single process stage and there are hundreds in a full wafer to get circuits to operate with the billion transistors or so now in production. IBM will have test circuits to allow the performance to be measured but they haven"t stated what the detailed performance they have got on their research website yet. As they state, they expect it to be in chips in 2009; it still has a bit of work to go," said Dr Douglas Paul, senior research associate at Cambridge University.