FABRICATION AND CHARACTERIZATION OF IGZO TFT

Abstract

This work mainly emphases on the fabrication of indium gallium zinc oxide (IGZO) Thin Film Transistor (TFT), in which the bottom gate IGZO TFTs were fabricated by RF sputter deposition. First, the gate dielectric was grown on p-doped silicon wafer by thermal oxidation. The silicon dioxide (SiO2) as a gate insulator, after that, the IGZO thin film active layers were deposited by RF sputter. Because RF sputters offer the advantages of a low manufacturing temperature and great uniformity on a huge scale, this deposition process is optimal for fabricating a-IGZO devices. The Aluminium (Al) as a gate source and drain electrodes, deposited by thermal evaporation. Then the devices were fabricated with different contact metal and annealing process. The electrical characterizations of IGZO TFTs were studied. The fabricated IGZO TFT were characterized by four probe I-V measurement system. IGZO based capacitors were also fabricated. On p-Si wafer aluminium metal layer is deposited by thermal evaporation and IGZO layer were deposited by RF sputter deposition method and again aluminium metal layer deposited in means of thermal evaporation. Capacitors were annealed in different annealing environment, as deposited, annealing at 3000 C in presence of Nitrogen and ozone annealing. IGZO based capacitors stack then characterized in LCR meter in Cp-G mode and Cp-D mode for four bias and four temperatures. I plotted the capacitance verse frequency plots and conductance verse frequency plots for all annealing process at different biasing voltage.