Nonvolatile memory apparatus including resistive-change material layer
A nonvolatile memory apparatus includes a first electrode, a second electrode separated from the first electrode, a resistive-change material layer provided between the first electrode and the second electrode and configured to store information due to a resistance change caused by an electrical signal applied through the first electrode and the second electrode, and a diffusion prevention layer provided between the first electrode and the resistive-change material layer and/or between the second electrode and the resistive-change material layer and including a two-dimensional (2D) material having a monolayer thickness of about 0.35 nm or less.
1. A nonvolatile memory apparatus comprising:
a first electrode;
a second electrode separated from the first electrode;
a resistive-change material layer between the first electrode and the second electrode and configured to store information due to a resistance change caused by an electrical signal applied through the first electrode and the second electrode;
a first diffusion prevention layer in contact with the second electrode and between the second electrode and the resistive-change material layer; and
a second diffusion prevention layer in contact with the first electrode and between the first electrode and the resistive-change material layer,
wherein at least one of the first diffusion prevention layer or the second diffusion prevention layer includes a two-dimensional (2D) material having a monolayer thickness of about 0.35 nm or less, and
wherein the first electrode is a plug electrode, and the first electrode is narrower than the resistive-change material layer.
2. The nonvolatile memory apparatus of claim 1 , wherein at least one of the first diffusion prevention layer or the second diffusion prevention layer is a graphene diffusion prevention layer comprising graphene.
3. The nonvolatile memory apparatus of claim 2 , wherein the graphene diffusion prevention layer has a thickness of about 0.5 nm to about 20 nm.
4. The nonvolatile memory apparatus of claim 2 , wherein the graphene diffusion prevention layer has a grain size of about 1 nm to about 20 nm.
5. The nonvolatile memory apparatus of claim 2 , wherein the graphene diffusion prevention layer has a grain size of about 20 nm or more.
6. The nonvolatile memory apparatus of claim 2 , further comprising an atomic layer deposition (ALD) layer on the graphene diffusion prevention layer.
7. The nonvolatile memory apparatus of claim 6 , wherein the ALD layer comprises one selected from among a metal, a nitride, and an oxide.
8. The nonvolatile memory apparatus of claim 7 , wherein the ALD layer comprises one selected from among Ru, TiN, TaN, TiAlN, AlO, InO, ZnO, AlZnO, InZnO, and RuAlO.
9. The nonvolatile memory apparatus of claim 1 , wherein at least one of the first diffusion prevention layer or the second diffusion prevention layer is a boron nitride (BN) diffusion prevention layer comprising BN.
10. The nonvolatile memory apparatus of claim 1 ,
wherein the second diffusion prevention layer is in direct contact with the first electrode or the first diffusion prevention layer is in direct contact with the second electrode.
11. The nonvolatile memory apparatus of claim 1 , wherein the resistive-change material layer is a phase-change layer configured to store information due to a resistance difference through a phase change.
12. The nonvolatile memory apparatus of claim 11 , wherein the resistive-change material layer comprises one phase-change material selected from among GeTe, GeSb, GeSbTe, AgInSbTe, and N—GeSbTe.
13. The nonvolatile memory apparatus of claim 11 , wherein the first electrode comprises at least one conductive material selected from among TiN, TaN, TiAlN, TaSiN, WN, WNC, and doped-Si.
14. The nonvolatile memory apparatus of claim 13 , wherein the second electrode comprises at least one conductive material selected from among Al, Au, Cu, Ir, Ru, Pt, Ti, TiN, Ta, and TaN.
15. The nonvolatile memory apparatus of claim 13 , further comprising a pad electrode in contact with the first electrode,
wherein the pad electrode comprises at least one conductive material selected from among Al, Au, Cu, Ir, Ru, Pt, Ti, TiN, Ta, and TaN.
16. The nonvolatile memory apparatus of claim 1 , wherein the resistive-change material layer is configured to store information due to a resistance difference through non-uniform diffusion of oxygen or a resistance difference through a filament formation.
17. The nonvolatile memory apparatus of claim 16 , wherein the resistive-change material layer comprises one selected from among HfO 2 , TaOx, TiOx, Ag—Si, Ag—GeS 2 , and ZrTe—Al 2 O 3 .
18. The nonvolatile memory apparatus of claim 16 , further comprising a pad electrode in contact with at least one of the first electrode or the second electrode.