SEMICONDUCTOR FERROELECTRIC MEMORY DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an MFIS memory device which can be put to practical use and retains data for a certain period of time. SOLUTION: An insulator buffer layer 2 is composed of HfO2+uor Hf1-xAl2xO2+x+yto reduce the leakage current from both of the insulation buffer layer 2 and a ferroelectric 3 and to provide a memory transistor which retains data for a good long time. This solves the problem that the data written in a conventional MFIS transistor vanishes within a day or a little longer mainly because large leakage current from the buffer layer and the ferroelectric prevents electric polarization of the ferroelectric from controlling electric conduction between the source drains of transistors in which electric charges are accumulated around an interface between the ferroelectric and the buffer layer so that they shield electric polarization stored in the ferroelectric. COPYRIGHT: (C)2005,JPO&NCIPI