Using Self-alignment Of The Fabricated Polysilicon Tft

With the development of display technology and the fabrication technique, high electric performance poly-Si TFTs were used broadly and considered as the perfect substitute for a -Si TFT. Comparing to a-Si TFT, p-Si TFT has the merits such as high field effect mobility, high integration and high speed, high definition display, n channel and p channel capability, low power consumption and self-aligned structures. With these good characteristics, p-Si TFT LCD could provide brighter and stable image. Especially because of p-Si TFT having the characteristic of working with p-channel and n- channel, it could be used in LCD display and OLED display. It is believed that p-Si TFT will be the main type in the future panel display.Among the process of manufacture p- Si TFT, the source and drain will have the superposition with grid for the reason of machine's alignment error. The superposition will bring superposition capacitance and it will badly cut down the electric performance. Making use of self–aligned structure could avoid the superposition capacitance. In this thesis, the method of self-aligned structure TFT was used to manufacture the p-Si TFT. The lithography and etching method were investigating. Finally the method of preparation of p-Si TFT and some useful dates were given.The dissertation includes seven chapters. The first chapter introduces the development of TFT; The second chapter introduces the principle of TFT and its structure; The third chapter provides the reason of superposition capacitance between S, D and gate; The fourth chapter introduce the deposition and test method of SiNx ; The fifth chapter introduces the fabrication of p-Si; The sixth chapter studies the fabrication techniques of p-Si TFT and some parameters; The seventh chapter is a conclusion of the research.