Low-Temperature Polysilicon Process Bodes Well For Flat-Panel Displays

Sept. 29, 2005

A joint venture promises a radically new approach to low-temperature silicon processing. It also signals a breakthrough for low-cost thin-film-transistor (TFT) flat-panel displays like organic LEDs (OLEDs) and LCD active-matrix displays. TCZ Inc. has combined the expertise of Cymer Inc., a deep-ultraviolet laser supplier, and Carl Zeiss SMT AG, a supplier of versatile optical systems for chip manufacturing and process control, to achieve this breakthrough.

TCZ's tool addresses the flat-panel display market. Its thin-beam directional crystallization (TDX) fills the void that holds back large-scale introduction of cost-effective system-on-a-panel (SOP) and systemon-glass (SOG) active-matrix LCDs and OLEDs. Leveraging the benefits of conventional excimer laser annealing (ELA) processing with those of sequential lateral solidification (SLS), it's part of the TCZ 900X system (Fig. 1).

In the new TDX approach, an optically created thin beam uses all available laser power. The higher-power laser drive (compared to conventional methods) provides a higher manufacturing throughput. The laser's long beam lets the system scan a flat panel's entire width without the stitching effects normally encountered with present methods. It also allows for lateral growth on a planar surface topology (Fig. 2).

"Cost trends are a major driving force in flat-panel displays. This is creating the need for higher-throughput, higher-yield, and lower-cost manufacturing processes, which we know will be made possible by our TCZ 900 system," explains TCZ's CEO, Brian Klene. "Yields and quality levels will increase up to twofold."

Klene expects normalized costs for OLEDs to drop below those of LCDs within a couple of years. Both technologies' costs will decline. For details, see ED Online 11123 at www.elecdesign.com. Also, the companies' Web sites feature a video of the process.

Cymer Inc.
www.cymer.com

TCZ Inc.
www.teamcymerzeiss.com

Zeiss SMT AG
www.smt.zeiss.com

About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.