Response surface optimization for high-performance solid-phase crystallized silicon-germanium thin film transistors

Vivek Subramanian; Krishna C. Saraswat; Howard Hovagimian; John C. Mehlhaff

doi:10.1117/12.270286

Translator Disclaimer

10 April 1997 Response surface optimization for high-performance solid-phase crystallized silicon-germanium thin film transistors

Vivek Subramanian, Krishna C. Saraswat, Howard Hovagimian, John C. Mehlhaff

Author Affiliations +

Proceedings Volume 3014, Active Matrix Liquid Crystal Displays Technology and Applications; (1997) https://doi.org/10.1117/12.270286
Event: Electronic Imaging '97, 1997, San Jose, CA, United States

Abstract

Silicon-Germanium (SiGe) is a promising material for polycrystalline thin film transistors (TFTs) for active matrix liquid crystal display applications due to its low thermal budget and temperature requirements. The use of SiGe as the channel material in a TFT allows for faster crystallization and dopant activation at lower temperatures than possible with pure silicon. Thus, a SiGe-based TFT technology has great promise as a high-performance, high throughput, uniform, glass-compatible TFT process. Analysis of the SiGe system is difficult due to its binary nature. This complicates the development of optimization strategies for performance enhancement. The numerous variable sand interactions affecting the SiGe system make a standard factorial characterization impractical. In this paper, we present the results of a reduced multifactorial response surface characterization of the system. The results obtained have been used to define optimization strategies for improving device performance. Tests have shown the strategies to be valid over a wide range of conditions. Using these strategies, n- and p-channel TFTs have been fabricated using a glass-compatible process and they exhibit substantially better performance than previously achieved using a similar thermal budget process. Further optimization using the determined guidelines would enable the development of a manufacturable high-performance poly-SiGe TFT process. Phenomena affecting the SiGe deposition system have also been identified, suggesting bounds on the optimization windows.

Citation Download Citation

Vivek Subramanian, Krishna C. Saraswat, Howard Hovagimian, and John C. Mehlhaff "Response surface optimization for high-performance solid-phase crystallized silicon-germanium thin film transistors", Proc. SPIE 3014, Active Matrix Liquid Crystal Displays Technology and Applications, (10 April 1997); https://doi.org/10.1117/12.270286

ACCESS THE FULL ARTICLE