A joint research team from Tohoku University and NEC Corp. has developed a new type of gas for manufacturing semiconductors that researchers say lessens the impact on global warming and raises precision chip production.

The gas, which can dissolve into carbon dioxide and other compounds a week after exposure to air, was developed as an alternative to perfluorocarbon (PFC), a gas introduced to chip-making as a replacement for ozone-destroying chlorofluorocarbon but is known to have severe global warming effects.

Seiji Samukawa, a professor at Tohoku University's Institute of Fluid Science and the research group leader, said PFC's effect on global warming is 8,700 times that of carbon dioxide and that it takes 2,600 years to break down.

The new gas not only decomposes easily through reaction with oxygen but can be used with existing chip-making facilities without modifications, Samukawa said.

On converting PFC into plasma, the Samukawa team succeeded in identifying two different particles, one with strong etching strength and the other with strong protection power for silicon chips.

The team developed the new chip-making gas by mixing the two gases that produce the chip-edging and chip-protecting particles.

The team said the new gas enhances the quality of silicon chips because it does not contain extraneous particles that would lower the precision of the manufacturing process.

Samukawa predicts the gas will be commercially available in a few years and will eventually replace PFC.