Effect of Low Temperature Processing on Polysilicon Thin Film Transistors Characteristics

多晶硅薄膜晶体管已成功应用于硬玻璃基板上的液晶显示器（软化点超过600摄氏度），证明了其电气特性适合此类应用。由于多晶硅晶体管需要较高的加工温度，因此采用了硬玻璃衬底。如果可以使用硼硅酸盐玻璃（康宁7059）作为衬底，可以实现显著的成本节约，特别是对于大型显示器。然而，硼硅酸盐玻璃的加工温度限制在575℃。这一限制影响了薄膜晶体管的电学性能。我们已经开发了一种低温（550摄氏度）工艺，用于制造多晶硅TFT。为了将其商业化用于显示应用，我们需要进一步研究衬底，等离子体掺杂和通道蚀刻的影响，以及选择最佳绝缘体。该技术有许多专利应用，如大面积显示器、成像仪、扫描仪和集成薄膜电子产品。

Polycrystalline silicon thin-film transistors have been successfully applied to liquid crystal displays on hard (softening point above 600 degrees c) glass substrate, demonstrating the adequacy of their electrical characteristics for such applications. Hard glass substrate were used because of the high processing temperatures needed for the polysilicon transistors. Significant cost savings could be realized, especially for large displays, if a borosilicate glass (Corning 7059) could be used as the substrate. However, borosilicate glass is limited to 575 degrees C processing temperature. This restriction affects the electrical properties of thin-film transistors. We have developed a low temperature (550 degrees C) process for fabricating polycrystal silicon TFT's. In order to commercialize it for display applications, we need to further investigate effects from the substrate, plasma doping, and channel etching as well as select the best insulator. There are numerous patented applications of this technique such as in Large-area displays, Imagers, Scanners, and Integrated thin-film electronics.