Researchers at Oregon State University have made a significant breakthrough in the technology to produce crystalline oxide films, which play roles in semiconductor chips, flat panel displays and many other electronic products.
In a report to be published in the journal Science, the OSU scientists explain a way to create these crystalline thin films at temperatures far lower than those used currently, and with no need to be produced in a vacuum as the current technology usually requires.
This fundamental advance may eventually open up important new applications in the electronics, computer and high technology industries, making new products possible or lowering the cost of those already being created.
According to Douglas Keszler, an OSU professor of chemistry, many electronic or photonic devices contain crystalline oxide films that can conduct electricity, serve as insulators or have desirable optical properties. To achieve crystallinity, it’s usually necessary to manufacture the films in high vacuum conditions and at temperatures of more than 1,800 degrees. Sophisticated equipment is needed to achieve both the vacuum condition and high temperature, and the process is expensive.
By contrast, the new approach discovered by OSU scientists and engineers uses a simple, water-based chemistry to deposit and crystallise these films at lower temperatures, about 250 degrees. No vacuum is necessary.
‘We found that you can take certain materials that contain water and let them dehydrate slowly and at low temperatures, and still observe crystallinity,’ Keszler said. ‘Processing is done in a bath, rather than requiring expensive technology, vacuums and very high temperatures. There has never been a way before to both deposit and crystallise electronic or photonic films at such low temperatures.’
The very need for such high manufacturing temperatures, the OSU researchers said, has in fact precluded the use of these electronic thin films on some applications, such as plastics, that would melt and be destroyed by temperatures of 1,800 degrees. And the new approach could also facilitate cheaper mass production of some products, whereas in the past the need for sophisticated technology and space constraints might have limited manufacturers to making one product or a few at a time.
According to John Wager, a co-author on the study and professor of electrical and computer engineering at OSU, it may take further research and increased collaboration with private industry to implement the new approach in large-scale commercial manufacturing processes. But the possibilities seem promising, he said.
‘It’s always difficult to predict exactly how a new technology will be received and used in manufacturing products,’ Wager said. ‘But clearly this offers some ways to reduce costs or create new products that never were possible before.’