Metal oxide alloy layer, method of forming the metal oxide alloy layer, and methods of manufacturing a gate structure and a capacitor including the metal oxide alloy layer

A method of manufacturing a gate structure, comprising:

• forming a first layer on a substrate, the first layer including a first metal oxide and having a first thickness for allowing the first metal oxide to move out of the first layer;
• forming a second layer on the first layer, the second layer including a second metal oxide and having a second thickness for allowing the second metal oxide to move out of the second layer;
• repeatedly forming the first and second layers wherein the first metal oxide and the second metal oxide move into the second layer and the first layer, respectively, to form a gate insulation layer having a single-layered structure in which the first and second metal oxides are mixed;
• forming a gate conductive layer on the gate insulation layer;
• and
• sequentially patterning the gate conductive layer and the gate insulation layer to form a gate pattern including a gate conductive layer pattern and a gate insulation layer pattern.