Resistive random access memory device and method for fabricating the same
A ReRAM device includes an interlayer dielectric (ILD), a lower conductive plug, a resistance-switching element (RSE) and an upper conductive plug. The ILD has an upper surface. The lower conductive plug is disposed in the ILD, and has a top surface lower than the upper surface. The RSE is disposed above the top surface and electrically contacts with the top surface. The upper conductive plug is disposed above the RSE and electrically contacts with the RSE.
1 . A resistive random access memory (ReRAM) device, comprising:
an interlayer dielectric layer (ILD), having an upper surface;
a lower conductive plug, disposed in the ILD and having a top surface lower than the upper surface;
a resistance-switching element (RSE), disposed above the top surface and electrically contacting with the top surface; and
an upper conductive plug, disposed above the RSE and electrically contacting with the RSE;
wherein the ILD has a through hole passing through the upper surface; the lower conductive plug is disposed in the through hole; the RSE at least partially extends into the through hole; and the RSE has a top substantially coplanar with the upper surface.
2 . A ReRAM device, comprising:
an interlayer dielectric layer (ILD), having an upper surface;
a lower conductive plug, disposed in the ILD and having a top surface lower than the upper surface;
a resistance-switching element (RSE), disposed above the top surface and electrically contacting with the top surface; and
an upper conductive plug, disposed above the RSE and electrically contacting with the RSE;
wherein the RSE comprises:
a lower electrode layer, electrically contacting with the top surface;
an upper electrode layer, electrically contacting with the upper conductive plug; and
a transition metal oxide (TMO) layer, disposed between the lower electrode layer and the upper electrode layer.
3 . The ReRAM device according to claim 2 , wherein the TMO layer comprises tantalum oxide (TaOx); the upper electrode layer comprises tantalum nitride (TaN) and iridium (Ir); the upper conductive plug comprises copper (Cu); and the lower conductive plug comprises tungsten (W).
4 . The ReRAM device according to claim 2 , wherein the TMO layer comprises a first TaOx sublayer disposed above the lower electrode layer and a second TaOx sublayer disposed above the first TaOx sublayer; and the first TaOx sublayer layer and the second TaOx sublayer have different oxygen contents.
5 . The ReRAM device according to claim 2 , wherein at least a portion of the upper electrode layer has a same level as the upper surface.
6 . The ReRAM device according to claim 2 , wherein the ILD has a through hole passing through the upper surface; the upper electrode layer fills a portion of the through hole lower than the upper surface.
7 . A ReRAM device, comprising:
an interlayer dielectric layer (ILD), having an upper surface;
a lower conductive plug, disposed in the ILD and having a top surface lower than the upper surface;
a resistance-switching element (RSE), disposed above the top surface and electrically contacting with the top surface; and
an upper conductive plug, disposed above the RSE and electrically contacting with the RSE;
wherein the ILD has a through hole passing through the upper surface; the lower conductive plug is disposed in the through hole; the RSE at least partially extends into the electrical through hole; and at least a portion of the upper conductive plug extends into the through hole.
8 . The ReRAM device according to claim 1 , wherein the RSE comprises:
a lower electrode layer, electrically contacting with the top surface;
an upper electrode layer, electrically contacting with the upper conductive plug; and
a TMO layer, disposed between the lower electrode layer and the upper electrode layer.
9 . The ReRAM device according to claim 8 , wherein the TMO layer comprises TaOx; the upper electrode layer comprises TaN and Ir; the upper conductive plug comprises Cu; and the lower conductive plug comprises W.
10 . The ReRAM device according to claim 8 , wherein the TMO layer comprises a first TaOx sublayer disposed above the lower electrode layer and a second TaOx sublayer disposed above the first TaOx sublayer; and the first TaOx sublayer layer and the second TaOx sublayer have different oxygen contents.
11 . The ReRAM device according to claim 8 , wherein at least a portion of the upper electrode layer has a same level as the upper surface.
12 . The ReRAM device according to claim 8 , wherein the upper electrode layer fills a portion of the through hole lower than the upper surface.
13 . The ReRAM device according to claim 2 , wherein the ILD has a through hole passing through the upper surface; and the lower conductive plug is disposed in the through hole.
14 . The ReRAM device according to claim 7 , wherein the RSE comprises:
a lower electrode layer, electrically contacting with the top surface;
an upper electrode layer, electrically contacting with the upper conductive plug; and
a transition metal oxide (TMO) layer, disposed between the lower electrode layer and the upper electrode layer.
15 . The ReRAM device according to claim 14 , wherein the TMO layer comprises tantalum oxide (TaOx); the upper electrode layer comprises tantalum nitride (TaN) and iridium (Ir); the upper conductive plug comprises copper (Cu); and the lower conductive plug comprises tungsten (W).
16 . The ReRAM device according to claim 14 , wherein the TMO layer comprises a first TaOx sublayer disposed above the lower electrode layer and a second TaOx sublayer disposed above the first TaOx sublayer; and the first TaOx sublayer layer and the second TaOx sublayer have different oxygen contents.
17 . The ReRAM device according to claim 14 , wherein the upper electrode layer fills a portion of the through hole lower than the upper surface.