Creating a film of silicon dioxide on the surface of silicon wafers is an important stage in chip manufacturing. Silicon dioxide films serve as an insulating layer into which electrical circuits are etched using photolithography. These films also serve as the "active gate layer" that helps switch the transistors.

Much like iron oxidizing into rust, silicon dioxide can also build up naturally when silicon is exposed to air. The process, however, is very slow at room temperature and so chip manufacturers bake silicon wafers in furnaces at up to 1,000 degrees centigrade to accelerate the process.

University College researchers have now found a way to speed up dioxide creation at room temperature using UV lamps. With these lamps, they create a suitable layer of dioxide in about the same amount of time it takes to blast the silicon in a furnace. A significant advantage with the process is that it could result in chip manufacturing becoming more efficient. When furnaces are used, components added to the chips earlier in the manufacturing process are likely to become diffused in the high temperatures.

Researchers struggled to identify the right type of UV light, experimenting for years with UV light at wavelengths of 122 nanometers and 172 nms. Since wavelengths at these ranges still required heating the silicon to 400 degrees, they reduced the wavelength to 126 nms, creating what researchers call "very deep UV." This "deep UV" they realised could create the dioxide at room temperature.

According to the researchers, when oxygen molecules are broken through UV radiation into two oxygen atoms at 200 nanometers or so, these atoms are not very aggressive oxidizers. But with this "very deep UV" that they have now developed, one of the atoms becomes an extremely aggressive oxidizer. This is they say is the secret of the success of their process. The process has yielded to the scientists dioxide films 10 nms to 15 nms thick, which is more than sufficient for CMOS chip manufacture. A nm is a billionth of a meter, or about the length of three atoms side by side.

The UV lamps themselves resemble the florescent light tubes used in offices and could be mass produced very easily. Right now they are at an early stage of development, researchers said, much like the early light bulbs.

Researchers will now test the properties of silicon dioxide in a clean room at the new London Center for Nanotechnology, to see its suitability for commercial use. The dioxide will now be tested to see how much voltage and current it can withstand before breaking down or becoming defective.

Researchers say it could very likely be several years before the technology becomes ready for commercial use. When it does the payoffs are likely to be significant, for the technique uses much less energy than a blast furnace and could result in savings of millions of dollars for chip manufacturers. This would allow them to reduce the prices of chips and make things cheaper for consumers down the line.