Methods for forming a capacitor on an integrated circuit device at reduced temperatures

A method of forming a capacitor comprising:

• forming a first conductive layer on a substrate;
• forming a reaction-preventing layer on the first conductive layer to prevent an oxidation at a temperature of not generating a phase change of the first conductive layer;
• forming a dielectric layer on the reaction preventing layer;
• and
• forming a second conductive layer on the dielectric layer.

A method of forming a capacitor comprising:

• forming an insulation layer pattern having a contact hole on a substrate having a lower structure;
• forming a first conductive layer continuously on a sidewall portion and a bottom portion of the contact hole and on the surface of the insulation layer pattern;
• removing the first conductive layer formed on the surface portion of the insulation layer pattern;
• removing the insulation layer pattern to allow the first conductive layer to remain on the sidewall portion and the bottom portion of the contact hole to form a cylindrical lower electrode;
• forming a reaction-preventing layer on the cylindrical lower electrode for preventing an oxidation at a temperature of not generating a phase change of the lower electrode;
• forming a dielectric layer on the reaction preventing layer;
• and
• forming a second conductive layer on the dielectric layer as an upper electrode.