Fabrication and Characterization of MFIS-FET Using Au/BLT/LZO/Si Structures

Abstract

We fabricated the n-channel metal-ferroelectric-insulator-semiconductor field-effect transistor (MFIS-FET) using an Au/(Bi,La) 4 Ti 3 O 12 /LaZrO x /Si(100) gate structure. We observed that the LaZrO x thin film had the equivalent oxide thickness value of around 8.7 nm. The 420-nm-thick (Bi,La) 4 Ti 3 O 12 film on a LaZrO x /Si structure, showed a good ferroelectric property and had the width of the memory window of 1.2 V for a bias voltage sweeping of ± 7 V. The drain current-gate voltage (I D -V G ) of an Au/(Bi,La) 4 Ti 3 O 12/ LaZrO x /Si(100) MFIS-FET showed threshold voltage shift (memory window width) owing to the ferroelectric (Bi,La) 4 Ti 3 O 12 film. The drain current-drain voltage (I D -V D ) characteristic curves exhibit typical n-channel field-effect transistor current-voltage characteristic. However, relatively large leakage current observed in the I D –V G and the I D –V D characteristic curves, might be caused by the high density of pores in the BLT film.