Semiconductor devices and method of manufacturing the same
A method of manufacturing a semiconductor device includes forming a preliminary lower electrode layer on a substrate, the preliminary lower electrode layer including a niobium oxide; converting at least a portion of the preliminary lower electrode layer to a first lower electrode layer comprising a niobium nitride by performing a nitridation process on the preliminary lower electrode layer; forming a dielectric layer on the first lower electrode layer; and forming an upper electrode on the dielectric layer.
1. A method of manufacturing a semiconductor device, the method comprising:
forming a preliminary lower electrode layer on a substrate, the preliminary lower electrode layer comprising a niobium oxide;
converting at least a portion of the preliminary lower electrode layer to a first lower electrode layer comprising a niobium nitride by performing a nitridation process on the preliminary lower electrode layer;
forming a dielectric layer on the first lower electrode layer; and
forming an upper electrode on the dielectric layer,
wherein the dielectric layer comprises a hafnium oxide, the hafnium oxide having a tetragonal crystalline phase resulting from the niobium nitride of the first lower electrode layer.
2. The method of claim 1 , wherein the first lower electrode layer comprises a niobium nitride (NbN x , 0.5≤x≤1), formed as oxygen in a niobium oxide is substituted with nitrogen.
3. The method of claim 1 , wherein the forming of the preliminary lower electrode layer comprises repeating a material layer forming cycle a plurality of times, and
the material layer forming cycle comprises:
feeding a first precursor source;
purging an excess first precursor source;
feeding a first oxidizer source; and
purging an excess first oxidizer source.
4. The method of claim 3 , wherein the first precursor source comprises a metal organic precursor including niobium or a halide precursor including niobium, and
the first oxidizer source is at least one of O 2 , O 3 , H 2 O, H 2 O 2 , and a plasma including oxygen.
5. The method of claim 1 , wherein the nitridation process comprises a plasma nitridation process or a thermal nitridation process.
6. The method of claim 1 , wherein
the forming of the preliminary lower electrode layer comprises:
forming a mold layer having an opening on the substrate; and
forming the preliminary lower electrode layer on the mold layer to cover an inner wall of the opening,
the converting of the at least a portion of the preliminary lower electrode layer to the first lower electrode layer comprises:
converting the portion of the preliminary lower electrode layer within a first thickness from a top surface of the preliminary lower electrode layer, exposed on the inner wall of the opening of the mold layer, in a first direction perpendicular to the top surface of the preliminary lower electrode layer to the first lower electrode layer by substituting nitrogen for oxygen in the portion of the preliminary lower electrode layer, and
a second thickness of the preliminary lower electrode layer in the first direction is greater than the first thickness of the first lower electrode layer.
7. The method of claim 1 , wherein the forming of the preliminary lower electrode layer comprises:
forming a mold layer having an opening on the substrate; and
forming a lower base layer on the mold layer to cover an inner wall of the opening; and
forming the preliminary lower electrode layer on the lower base layer to cover the inner wall of the opening.
8. The method of claim 1 , wherein
the forming of the preliminary lower electrode layer comprises:
forming a mold layer having an opening on the substrate; and
forming the preliminary lower electrode layer on the mold layer to cover an inner wall of the opening, and
the converting of the at least a portion of the preliminary lower electrode layer to the first lower electrode layer comprises:
converting the preliminary lower electrode layer throughout a thickness thereof from a top surface of the preliminary lower electrode layer, exposed on the inner wall of the opening, in a first direction perpendicular to the top surface of the preliminary lower electrode layer to the first lower electrode layer by substituting nitrogen for oxygen in an entirety of the preliminary lower electrode layer.
9. The method of claim 1 , further comprising:
repeatedly performing the forming of the preliminary lower electrode layer and the converting of the preliminary lower electrode layer to the first lower electrode layer.
10. The method of claim 1 , wherein the forming of the preliminary lower electrode layer comprises:
forming a mold layer having an opening on the substrate;
forming the preliminary lower electrode layer on the mold layer to cover an inner wall of the opening; and
removing the mold layer.
11. The method of claim 1 , wherein the forming of the preliminary lower electrode layer comprises:
forming a mold layer having an opening on the substrate;
forming a lower base layer on the mold layer to fill an interior of the opening;
removing the mold layer; and
forming the preliminary lower electrode layer on an exposed surface of the lower base layer.
12. The method of claim 1 , wherein the tetragonal crystalline phase of the hafnium oxide results from an amount of interfacial energy between a surface of the dielectric layer and a surface of the first lower electrode layer.
13. A method of manufacturing a semiconductor device, the method comprising:
forming a mold layer having an opening on a substrate;
forming a preliminary lower electrode layer on the mold layer, the preliminary lower electrode layer covering an inner wall of the opening of the mold layer and comprising a niobium oxide;
converting at least a portion of the preliminary lower electrode layer to a first lower electrode layer comprising a niobium nitride by performing a nitridation process on the preliminary lower electrode layer;
forming a dielectric layer on the first lower electrode layer; and
forming an upper electrode layer on the dielectric layer,
wherein the dielectric layer comprises a hafnium oxide, the hafnium oxide having a tetragonal crystalline phase resulting from the niobium nitride of the first lower electrode layer.
14. The method of claim 13 , wherein the forming of the preliminary lower electrode layer comprises repeating a material layer forming cycle a plurality of times, and
the material layer forming cycle comprises:
feeding a first precursor source;
purging an excess first precursor source;
feeding a first oxidizer source; and
purging an excess first oxidizer source.
15. The method of claim 14 , wherein the first precursor source comprises a metal organic precursor including niobium or a halide precursor including niobium,
the first oxidizer source is at least one of O 2 , O 3 , H 2 O, H 2 O 2 , and a plasma including oxygen, and
the nitridation process comprises a plasma nitridation process or a thermal nitridation process.
16. The method of claim 13 , wherein the tetragonal crystalline phase of the hafnium oxide results from an amount of interfacial energy between a surface of the dielectric layer and a surface of the first lower electrode layer.
17. A method of manufacturing a semiconductor device, the method comprising:
forming a preliminary lower electrode layer on a substrate, the preliminary lower electrode layer comprising a niobium oxide;
converting at least a portion of the preliminary lower electrode layer to a first lower electrode layer comprising a niobium nitride by performing a plasma nitridation process on the preliminary lower electrode layer;
forming a dielectric layer on the first lower electrode layer, the dielectric layer comprising a hafnium oxide, a portion of the dielectric layer in contact with the first lower electrode layer comprises a hafnium oxide having a tetragonal crystalline phase resulting from the niobium nitride of the first lower electrode layer; and
forming an upper electrode on the dielectric layer.
18. The method of claim 17 , wherein the first lower electrode layer comprises a niobium nitride (NbN x , 0.5≤x≤1), formed as oxygen in a niobium oxide is substituted with nitrogen.
19. The method of claim 17 , wherein,
in the converting of the preliminary lower electrode layer to the first lower electrode layer, a portion of the preliminary lower electrode layer remains below the first lower electrode layer.
20. The method of claim 17 , wherein the tetragonal crystalline phase of the hafnium oxide results from an amount of interfacial energy between a surface of the portion of the dielectric layer and a surface of the first lower electrode layer.