Integrated circuit device

An integrated circuit device comprising:

• a transistor on a substrate;
• and
• a capacitor structure electrically connected to the transistor, wherein the capacitor structure includes:
• a first electrode;
• a dielectric layer structure on the first electrode;
• and
• a second electrode on the dielectric layer structure,
• wherein the dielectric layer structure includes a plurality of first dielectric layers and a plurality of second dielectric layers which are alternately stacked,
• wherein each of the plurality of first dielectric layers includes an anti-ferroelectric material containing a metal A and oxygen, and
• wherein each of the plurality of second dielectric layers includes a ferroelectric material containing the metal A, a metal B, and oxygen, and includes AxB1-xO2 in which 0<x<0.5, wherein an x value gradually changes in a stack direction inside each of the plurality of second dielectric layers.

An integrated circuit device comprising:

• a word line in a word line trench extending in a first direction inside a substrate;
• a contact structure on one side of the word line on the substrate;
• and
• a capacitor structure on the contact structure and electrically connected to the contact structure, wherein the capacitor structure includes:
• a first electrode on the contact structure;
• a dielectric layer structure covering the first electrode;
• and
• a second electrode on the dielectric layer structure,
• wherein the dielectric layer structure includes a plurality of anti-ferroelectric material layers and a plurality of ferroelectric material layers which are alternately stacked, and
• wherein each of the plurality of ferroelectric material layers includes Hf1-xZrxO2 in which 0<x<0.5, wherein an x value increases by a unit of 0.1 in a stack direction inside each of the plurality of ferroelectric material layers.