GATE STACK OF FERROELECTRIC MEMORY FIELD EFFECT TRANSISTOR AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A gate stack of a ferroelectric memory FET(Field Effect Transistor) and a manufacturing method thereof are provided to be capable of optimizing the electrical characteristics of the device. CONSTITUTION: A gate stack(25) of a ferroelectric memory FET is provided with a semiconductor substrate(11) and a diffusion barrier(19) formed on the semiconductor substrate. At this time, the diffusion barrier is completed by sequentially forming a silicon oxide layer(13), a silicon nitride layer(15), and a silicon oxide layer(17). The gate stack further includes a Bi-La-Ti-O ferroelectric layer(21) formed on the diffusion barrier and an upper electrode(23) formed on the ferroelectric layer. Preferably, a (BixLa1-x)4Ti3O12 layer is used as the ferroelectric layer.