Faster Transistors for IBM

IBM Corp. says it has perfected a technique for making faster transistors, opening the door to advanced microprocessors.

The advance, to be reported this week at a conference in Washington, will make long-sought “double-gate” transistors economical in chip manufacturing within five years, said Bijan Davari, IBM’s vice president of semiconductor development. As a result, chip performance probably will improve by 30% to 100%, Davari said.

Double-gate transistors help speed and control electrical flow across tiny gaps that create on-off switches so microprocessors can compute.

While advances in materials and chip design continue to produce faster chips, finding economical ways to manufacture the new designs has often been a stumbling block.

Today’s chips can hold millions of transistors, each an on-off switch using a single gate to control electron flow. As transistors have shrunk, scientists have found that electron leakage often allowed the transistor to stick in the “on” position.

Adding a second gate to better control the flow lets the transistor work properly without leakage, at higher speeds.

Among the key challenges has been finding ways to precisely align two gates opposite one another.

IBM has developed a technique for wrapping polysilicon, which conducts electricity, around a layer of silicon dioxide, a nonconductor, so that the gates are perfectly aligned, Davari said.