Im Featured in Columbia News

Prof. James Im was featured in the Columbia News article "Columbia, Motorola Sign Research Agreement on SLS Technology" by James Devitt.

Columbia and Motorola Labs have signed a one-year, extendable agreement to collaborate in research intended to extend Columbia's sequential lateral solidification (SLS) technology into the area of controlled crystal orientation.

The agreement seeks to improve the patented SLS technology to produce substrates suitable for use with Motorola's semiconductor fabrication technologies. For many semiconductor applications, single crystal silicon wafers serve as substrates. With the application of the SLS technology, a variety of alternative substrates can be developed to address specific market requirements. For example, low cost materials, such as glass or plastic, could be used for a wide range of integrated circuits. This development could open up new applications for low-cost lightweight high-performance electronic devices.

Michael Cleare, executive director of Columbia's Science & Technology Ventures (S & TV), expressed his satisfaction in the establishment of the relationship with Motorola Labs.

"We are delighted that such an important player in the global microelectonics industry as Motorola has recognized the potential of the SLS process in modifying the properties of semiconductor layers on a variety of substrates," Cleare said. "Motorola Lab's research capabilities in this area, when combined with the work of Professor James Im here at Columbia, will greatly increase the chances of finding new applications."

S & TV facilitates the transfer of scientific discovery and innovation from Columbia researchers to the marketplace. Motorola executives also praised the agreement with Columbia. "Motorola is pleased to be working in collaboration with Professor Im to produce novel substrates that we hope will lead to a broad family of semiconductor devices with unique advantages," said Iwona Turlik, corporate vice president and director of the Motorola Advanced Technology Center.

SLS is a process for producing high quality crystalline silicon films. When silicon is layered on glass or plastic substrates, it forms an amorphous layer, with poor electronic properties. SLS transforms amorphous silicon into its crystalline form through a process involving the application of laser energy to melt the silicon film over a specified area. The heat that is generated is confined to a small area of the film for a brief period, so that the temperature tolerances of the substrate are never exceeded. The SLS process controls the ensuing crystallization such that low defect density crystalline films are obtained. However, there are several possible planes of orientation of the crystals with respect to the surface of the film. Up to this time, no extensive attempt has been made to establish a known orientation. In this research collaboration, Columbia and Motorola Labs will seek to extend the process to create silicon films with a known and selectable crystal orientation.

The Columbia team is headed by Professor James Im of the University's Materials Science Department. Im's development of SLS has solved one of the most difficult problems in creating high-quality crystalline silicon films on glass or plastic substrates. The resulting films provide the base semiconducting layer for the fabrication of thin film transistors (TFTs), which control the pixels in active matrix liquid crystal displays (LCDs) and Organic Light Emitting Diode Displays (OLEDs).

Im's SLS technology can provide LTPS-based LCD and OLED flat-panel display producers with a number of technical advantages. These include higher yields, greater uniformity and responsiveness, and the capability of integrating control circuitry on the display panel.

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