Fabrication of Metal/Ferroelectric/Insulator/Semiconductor Field Effect Transistor Using Mo/Pb(Zr,Ti)O 3 /ZrTiO 4 /Poly Si Thin Film Structure

Abstract

In this work, metal/ferroelectric/insulator/semiconductor field effect transistors (MFISFET) using Mo/Pb(Zr,Ti)O 3 (PZT)/ZrTiO 4 (ZT)/polycrystalline Si (poly-Si) thin film structures were fabricated and characterized for nonvolatile nondestructive read-out (NDRO) memory devices. The 300 nm-thick PZT films were deposited by reactive RF magnetron sputtering method on ZrTiO 4 (50 nm)/Si substrates. After annealing process at 600 for crystallization of PZT thin films, there was no inter-diffusion of Pb and Si. C-V hysteresis was observed in Pt/PZT/ZrTiO 4 /Si (MFIS) structures. For fabricating memory device, we used thin film transistor (TFT) with poly-Si thin film. The amorphous Si thin films on SiO 2 substrates were crystallized by MILC (Metal Induced Lateral Crystallization) method at low temperature as 550 . The drain current-gate voltage (I D -V G ) characteristics of MFISFET using the Mo/PZT/ZrTiO 4 /poly-Si thin film structures showed threshold hysteresis due to the ferroelectric property of the PZT thin films. The threshold hysteresis value, i.e. memory window was about 0.6 V in the applied gate voltage range of 5 V, and almost same as C-V hysteresis value in MFIS structure.