Amorphous Silicon Thin Film Transistors on Kapton Fibers

摘要

The textile industry uses weaving to create very large quantities of fabric very quickly. The goal of our research is to use this well established technology to create complex large-area circuits quickly and efficiently. In our laboratory we have previously shown that amorphous silicon (a-Si) can be used to make thin-Film transistors (TFTs) on Kapton (a highly temperature-resistant polyimide from DuPont). We also previously showed that these TFTs can survive mechanical loads. A process has been designed to make "TFT fibers" by fabricating a-Si TFTs on Kapton. A special TFT geometry has also been developed. The structure consists of 3 large gold contact pads - one for each terminal of the TFT - running along the fiber. These contact pads allow connections to be made between TFT fibers using conductor fibers -Kapton fibers coated only with gold. The TFT fabrication process is based on a low temperature (150 °C) Plasma Enhanced Chemical Vapor Deposition (PECVD) process. The TFTs are fabricated on a Kapton sheet from which flat fibers are made by the slit film technique. So far the best method for cutting a Kapton sheet into fibers has been plasma etching. We will describe the electronic characteristics of these TFTs as well as the electrical characteristics of the contacts between TFT fibers.