SEMICONDUCTOR MEMORY DEVICE, AND METHOD FOR PRODUCING THE SAME

摘要

Provided is a semiconductor memory device (resistance random access memory element) improved in properties. A Ru film is formed as a film of a lower electrode by sputtering, and a Ta film is formed thereonto by sputtering. Next, the Ta film is oxidized with plasma to oxidize the Ta film. In this way, a compound Ta2O5 is produced and further Ru is diffused into the compound to form a layer (variable resistance layer) in which Ru is diffused into the compound Ta2O5. Such an incorporation of a metal (such as Ru) into a transition metal oxide TMO (such as Ta2O5) makes it possible to form electron conductive paths additional to filaments to lower the filaments in density and thickness. Thus, the memory element can be restrained from undergoing OFF-fixation, by which the element is not easily lowered in resistance, to be improved in ON-properties.

主权项

1. A semiconductor memory device, comprising:
a first electrode; a second electrode; and a variable resistance layer arranged between the first and second electrodes; wherein the variable resistance layer comprises an oxide layer of a first metal, and a second metal contained in the oxide layer of the first metal, wherein the first metal is a transition metal; and wherein the second metal is a metal that produces an electronic level inside a band gap of the oxide layer of the first metal.