The Varsity

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U of T may have the answer to a multi-billion dollar question

By Qing Hua Wang
Published: 10:00 am, 6 November 2003
Modified: 5 pm, 11 January 2012

Researchers at U of T have developed a new kind of material that may be used in the manufacture of faster and smaller computer chips.

A new material is needed to replace silica as the insulation around the wires in chips, and many groups around the world are working to develop a possible replacement. The material to succeed silica will “solve a multi-billion dollar problem,” says Professor Geoffrey Ozin of U of T’s Department of Chemistry and head of the lab. “Some material out there is going to be the material of choice, we don’t know if it’s going to be this one, but it’s a contender,” he adds.

The material he and his team have created is a combination of organic and inorganic elements. The organic component in the new composite is what will allow researchers to give it a huge variety of ‘designer properties,’ by changing the nature of the organic component. Organic materials are carbon-containing molecules, and although many of them were originally only found in nature, they can now be synthesized in the lab. Inorganic materials are simply molecules that do not contain carbon. Organic compounds are made up of only a few types of atoms-carbon, hydrogen, oxygen, nitrogen, and sulfur, mostly–but there are infinitely many arrangements because carbon can form long, branched chains and rings.

The combination of organic and inorganic elements in the new material allows researchers to “create something new [whose] properties transcend the properties of the parts,” says Professor Geoffrey Ozin of the Department of Chemistry, whose lab has been working on composite materials like this for a long time. The new composite is called a mesoporous material because it has pores on the meso scale (anywhere from 2 to 50 billionths of a meter). The new development was reported in an article published in the October 10 issue of the journal Science. Kai Landskron, a post-doctoral fellow in Ozin’s lab, was first author on the article.

One of the most important potential applications of the new material will be as an insulating material in computer chips. Currently, scientists are working to create smaller and therefore faster computer chips. As the components on a computer chip become smaller, the tiny wires carrying electricity become thinner and closer together. Insulators around the wires are needed to keep the electricity flowing fast. The material created by Ozin’s lab is essentially a better insulator than silica, which is currently used as the main insulating material in computer chips.

The properties of material were tested by researchers in the Materials Science Engineering department, PhD student Benjamin Hutton and Professor Doug Perovic. The electrical and mechanical features of the material were tested. The material was found to be relatively stiff, which makes it suitable for various engineering purposes. Further tests, now underway, will examine the material’s performance in actual circuits, and will be crucial to determining whether it will be a viable successor to silica.

The material was built up from a ring-shaped molecule that formed into a porous material by self-assemblyÑthe molecules arranged themselves spontaneously into a regular pattern. That is, it was built “bottom-up.”

Self-assembly is the cunning way in which nature constructs complex structures out of simple building blocks. Molecules often have characteristic features on them that make them ‘stick’ together in certain ways to form structures. Current methods of forming small structures, such as lithography, involve essentially cutting down larger structures into smaller ones. They are more wasteful and are reaching their limits of effectiveness. “So why not do it the way mother nature has been doing it for four billion years,” says Perovic. “We don’t think of materials anymore, we think of building blocks and synthesizing systems that auto-construct,” says Ozin.