Universal Amorphous Semiconductor Thin Film Transistor Compact Model And Parameter Extraction Tool

Amorphous semiconductor thin film transistors(a-TFTs)have been widely applied in many commercial display products,such as smart phones,flat panel displays and e-papers.Traditional amorphous silicon(a-Si)TFT is still the mainstream TFT technology.With the development of the semiconductor material science and device fabrication technology,the novel a-TFTs develops rapidly.Among this,amorphous oxide(a-oxide)TFTs and amorphous organic TFTs(a-OTFTs)are the hotspot of academic research and industrial application,attribute to their advantages of low cost,high uniformity and excellent mechanical flexibility.A-TFTs have broad application foreground in sensors,smart tags and flexible displays thanks to their cost and performance advantages.To meet the requirement of more complex a-TFTs circuits design,a universal a-TFTs compact model should be deduced applied to various device structure and amorphous semiconductor material.The similar subgap energy distribution and work mechanism of a-TFTs is the basis of building a universal model.At present,there is a lack of widely accepted aTFTs circuit simulation model.Both of the tradition a-Si TFT model and other TFT models specially aimed at particular novel semiconductor material can't meet the requirements of briefness,universality,accuracy,continuity and physics at the same time.This thesis will deduce universal above-threshold and subthreshold current formula,establish an accurate and universal a-TFTs(UATFT)compact model.UATFT model has fewer parameters which are convenient to extract.Besides of 3 fitting parameters,all the parameters have their common physical meanings.UATFT model can be applied to the circuit simulation of IGZO a-oxide TFT,small molecule TFT and organic polymer TFT.In order to facilitate the parameter extraction,a parameter extraction tool is developed independent of the Spice simulation software.This tool uses an iterative algorithm,which is different from the Spice ones,to calculate the simulation results and fit the experiment data quickly.