Metal-ferroelectric-semiconductor field-effect transistor (MPSFET) for single transistor memory by using Poly-Si source/drain and BaMgF/sub 4/ dielectric

The structure and electrical characteristics of a metal-ferroelectric-semiconductor field-effect transistor (MFSFET) for a single transistor memory are presented. We developed a novel MFSFET with polysilicon islands as source/drain electrodes and a BaMgF/sub 4/ film as gate dielectric. The polysilicon source and drain were formed prior to the deposition of BaMgF/sub 4/ to prevent the ferroelectric material from degradation due to high thermal cycling. Ferroelectric hysteresis measurement using a modified Sawyer-Tower circuit yielded remanent polarization and coercive field values of about 0.6 /spl mu/C/cm/sup 2/ and 80 kV/cm, respectively. The fabricated MFSFET also showed a good I-V hysteresis curve, confirming the usefulness of the proposed structure for ferroelectric memory transistors.