Process optimization of a-IGZO thin film transistors

Amorphous Oxide Semiconductors (AOS) exhibit high mobility, transparency and large area uniformity which makes it an ideal material to be researched and employed in large area electronics. Thin film transistors based on, amorphous Indium-Gallium-Zinc- Oxide (a-IGZO) semiconductors are valued for their low temperature processing and the above mentioned characteristics. Modern advancements in the display technologies such as AMOLEDs (Active Matrix Organic Light Emitting Diode) and AMLCDs (Active Matrix Liquid Crystal Display) are the recent significant contributions of IGZO TFT’s.I carried out this project with the goal of optimizing the results of the Output Characteristics provided by the present IGZO TFT’s. I worked towards this goal by integrating different TFT structures and optimizing the integration steps in the process depending upon the results obtained during the progression. Various parameters in the integration process includes material used as AOS, thickness of the AOS deposited, technique used in AOS deposition, material used for S/D contacts, thickness and technique used for deposition of gate dielectric. Amongst the above mentioned parameters, TFT architecture type followed for the integration process plays a particular role. Extent of influence in enhancements steps like annealing was also examined and improvised. I followed the TFT integration steps based on the study conducted by my supervisor, Dr. Manoj Nag on the process technology for integration of a-IGZO thin film transistors