One-transistor (1T) memory devices with MFIS (Metal, Ferroelectrics, Insulator, Silicon) and MFMIS (Metal, Ferroelectrics, Metal, Insulator, Silicon) structures have been widely studied. These memory devices exhibit memory working functions but very poor retention properties. Three possible mechanisms are responsible for the poor retention of 1 T ferroelectric memories: namely, charges trapping within the gate oxide and ferroelectric film, floating gate effect, and the depolarization field. In order to overcome these problems, a novel ferroelectric transistor design using a semiconductive oxide film in place of the gate dielectric has been fabricated. The device structures are Pt/PGO/InO2/Si (MFSoxS) and Pt/PGO/Ir/InO2/Si (MFMSoxS). There is no insulator in the gate stack. These device structures do not have floating gate and the depolarization field is very low. Therefore, the memory retention time can be very long. In this paper, we report the device structures, integration processes and the working properties with improved retention properties of the Pt/PGO/InO2/Si (MFSoxS) and Pt/PGO/Ir/InO2/Si (MFMSoxS) devices.