Method for manufacturing a non-volatile memory device

A method for manufacturing a nonvolatile ferroelectric memory device comprising the steps of:

• selectively forming a device isolation layer on a semiconductor substrate to define an active region;
• forming first and second split wordlines on a first insulating layer formed on the active region and the device isolation layer;
• forming first source/drain impurity regions of second conductivity types at both sides of the first split wordline and second source/drain impurity regions of second conductivity types at both sides of the second split wordline;
• forming a second insulating layer on an entire surface including the first and second split wordlines;
• forming first and second plug layers to be respectively connected with the first and second drain impurity regions by passing through the second insulating layer;
• forming a first bitline connected with the first plug layer and a second bitline connected with the second plug layer to cross the first and second split wordlines;
• forming a third insulating layer on the entire surface including the first and second bitlines;
• forming third and fourth plug layers respectively connected with the first and second source impurity regions by passing through the third insulating layer;
• forming first and second pad layers respectively connected with the third and fourth plug layers;
• forming a fourth insulating layer on the entire surface including the first and second pad layers;
• forming a trench on the fourth insulating layer to expose the first and second pad layers;
• forming first and second barrier metal layers at both sides of the exposed first and second pad layers and the trench;
• forming a lower electrode of a first ferroelectric capacitor on the first barrier metal layer over the second split wordline and a lower electrode of a second ferroelectric capacitor on the second barrier metal layer over the first split wordline;
• respectively forming first and second ferroelectric films on the lower electrodes of the first and second ferroelectric capacitors;
• and
• forming an upper electrode of the first ferroelectric capacitor on the first ferroelectric film and an upper electrode of the second ferroelectric capacitor on the second ferroelectric film.