Phase change layer and method of manufacturing the same and phase change memory device comprising phase change layer and methods of manufacturing and operating phase change memory device

A method of forming a phase change layer, comprising:

• preparing a co-sputtering target including first and second targets within a reaction chamber that is used for sputtering deposition of the phase change layer;
• loading a substrate on which the phase change layer will be formed into the reaction chamber;
• and
• applying first and second radio frequency (RF) power to the first and second targets, respectively.

A method of operating a phase change memory device comprising:

• maintaining a switching element in an ON state;
• and
• applying an operating voltage to a storage node including a phase change layer and connected to the switching element,
• wherein the phase change layer is formed of a quaternary compound including an amount a of indium (In) in a range of about 15 at. %≦a≦about 20 at. %.