Switching element, switching element manufacturing method, semiconductor device, and semiconductor device manufacturing method

A semiconductor device comprising a non-volatile resistive-change element and a volatile resistive-change element within a multilayer copper wiring layer on a semiconductor substrate, wherein

• the multilayer copper wiring layer comprises copper wiring and a copper plug,
• the non-volatile resistive-change element comprises a first electrode, a second electrode, and an ion conductive layer provided between the first electrode and the second electrode,
• the copper wiring serves as the first electrode and comprises a barrier insulating film provided thereon,
• the barrier insulating film contains silicon carbonitride,
• the barrier insulating film comprises an opening which reaches the first electrode,
• the opening comprises the ion conductive layer and the second electrode,
• the ion conductive layer comprises a first ion conductive layer in contact with the first electrode and a second ion conductive layer in contact with the second electrode,
• the first ion conductive layer comprises a material selected from the group consisting essentially of titanium oxide, aluminum oxide, and a stack of titanium oxide and aluminum oxide,
• the second ion conductive layer comprises a polymer film containing silicon, oxygen, and carbon and having a relative dielectric constant of 2.1 (inclusive) to 3.0 (inclusive),
• the second electrode comprises a material selected from the group consisting essentially of an alloy of ruthenium and tantalum and an alloy of ruthenium and titanium,
• the volatile resistive-change element comprises the second electrode, the third electrode, and a resistive-change layer provided between the second electrode and the third electrode,
• the opening comprises the resistive-change layer and the third electrode,
• the resistive-change layer comprises a material selected from the group consisting essentially of titanium oxide, aluminum oxide, tantalum oxide, niobium oxide, and a stack of titanium oxide, aluminum oxide, tantalum oxide, and niobium oxide,
• the third electrode is connected to the copper plug via a barrier metal,
• the third electrode contains tantalum, and
• the semiconductor device comprises an insulating material at least on a side surface of the third electrode.

A method for manufacturing a semiconductor device comprising a non-volatile resistive-change element and a volatile resistive-change element within a multilayer copper wiring layer on a semiconductor substrate, the method comprising:

• forming a barrier insulating film containing silicon carbonitride on copper wiring serving as a first electrode,
• forming in the barrier insulating film, an opening which reaches the first electrode,
• forming in the opening, a first ion conductive layer comprising a material selected from the group consisting essentially of titanium oxide, aluminum oxide, and a stack of titanium oxide and aluminum oxide,
• forming a polymer film containing silicon, oxygen, and carbon and having a relative dielectric constant of 2.1 (inclusive) to 3.0 (inclusive) on the first ion conductive layer as a second ion conductive layer,
• forming on the second ion conductive layer, a second electrode comprising a material selected from the group consisting essentially of an alloy of ruthenium and tantalum and an alloy of ruthenium and titanium,
• forming on the second electrode, a resistive-change layer comprising a material selected from the group consisting essentially of titanium oxide, aluminum oxide, tantalum oxide, niobium oxide, and a stack of titanium oxide, aluminum oxide, tantalum oxide, and niobium oxide,
• forming a third electrode containing tantalum on the resistive-change layer,
• forming a hard mask film containing silicon nitride and silicon oxide on the third electrode,
• forming a photoresist pattern on the hard mask film,
• forming a hard mask by performing dry etching on the hard mask film by an etching gas containing carbon tetrafluoride, using the photoresist pattern as a mask, and
• performing dry etching on the third electrode, the resistive-change layer, the second electrode, the second ion conductive layer, and the first ion conductive layer by an etching gas possessing oxidizing property, using the hard mask as a mask.