Ferroelectric memory device, manufacturing method of the ferroelectric memory device and semiconductor chip
A ferroelectric memory device, a manufacturing method of the ferroelectric memory device and a semiconductor chip are provided. The ferroelectric memory device includes a gate electrode, a ferroelectric layer, a channel layer, first and second blocking layers, and source/drain electrodes. The ferroelectric layer is disposed at a side of the gate electrode. The channel layer is capacitively coupled to the gate electrode through the ferroelectric layer. The first and second blocking layers are disposed between the ferroelectric layer and the channel layer. The second blocking layer is disposed between the first blocking layer and the channel layer. The first and second blocking layers comprise a same material, and the second blocking layer is further incorporated with nitrogen. The source/drain electrodes are disposed at opposite sides of the gate electrode, and electrically connected to the channel layer.
1. A ferroelectric memory device, comprising:
a gate electrode;
a ferroelectric layer, disposed at a side of the gate electrode;
a channel layer, capacitively coupled to the gate electrode through the ferroelectric layer;
a first blocking layer and a second blocking layer, disposed between the ferroelectric layer and the channel layer, wherein the second blocking layer is disposed between the first blocking layer and the channel layer, the first and second blocking layers comprise a same material, and the second blocking layer is further incorporated with nitrogen; and
source/drain electrodes, disposed at opposite sides of the gate electrode, and electrically connected to the channel layer.
2. The ferroelectric memory device according to claim 1 , wherein the same material contained in the first and second blocking layers results in band offset at an interface of the channel layer and the first and second blocking layers.
3. The ferroelectric memory device according to claim 1 , wherein the same material contained in the first and second blocking layers comprises an oxide ferroelectric material.
4. The ferroelectric memory device according to claim 1 , wherein the same material contained in the first and second blocking layers is doped with at least one material having a bandgap higher than a bandgap of a material of the channel layer.
5. The ferroelectric memory device according to claim 1 , wherein the first and second blocking layers both comprise hafnium oxide, and the second blocking layer is further incorporated with nitrogen.
6. The ferroelectric memory device according to claim 1 , further comprising:
a buffer layer and a seed layer, lining between the ferroelectric layer and the gate electrode, wherein the buffer layer is arranged to reduce lattice mismatch at an interface defined between the ferroelectric layer and the gate electrode, and the seed layer is arranged to enhance an orthorhombic crystalline phase fraction in the ferroelectric layer.
7. The ferroelectric memory device according to claim 1 , further comprising:
a third blocking layer, extending between the ferroelectric layer and the gate electrode, and formed of a material incorporated with nitrogen.
8. The ferroelectric memory device according to claim 1 , further comprising:
an additional gate electrode, disposed at a side of the channel layer facing away from the first and second blocking layers, and located between the source/drain electrodes; and
an additional ferroelectric layer, extending between the additional gate electrode and the channel layer, wherein the source/drain electrodes penetrate through the additional ferroelectric layer to establish contact with the channel layer.
9. The ferroelectric memory device according to claim 8 , further comprising:
a fourth and a fifth blocking layers, sandwiched between the channel layer and the additional ferroelectric layer, and penetrated by the source/drain electrodes, wherein the fourth and fifth blocking layers comprise a same material, and the fifth blocking layer is further incorporated with nitrogen.
10. The ferroelectric memory device according to claim 9 , wherein the fifth blocking layer is disposed between the channel layer and the fourth blocking layer.
11. The ferroelectric memory device according to claim 1 , further comprising:
a floating gate layer, disposed between the ferroelectric layer and the first blocking layer.
12. The ferroelectric memory device according to claim 11 , further comprising:
an additional floating gate layer, disposed at a side of the channel layer facing away from the second blocking layer, and located between the source/drain electrodes;
an additional ferroelectric layer, disposed at a side of the additional floating gate layer facing away from the channel layer, and located between the source/drain electrodes; and
an additional gate electrode, disposed at a side of the additional ferroelectric layer facing away from the additional floating gate layer, and located between the source/drain electrodes.
13. The ferroelectric memory device according to claim 12 , further comprising:
a sixth and a seventh blocking layers, sandwiched between the channel layer and the additional ferroelectric layer, and located between the source/drain electrodes, wherein the sixth and seventh blocking layers comprise a same material, and the seventh blocking layer is further incorporated with nitrogen.
14. The ferroelectric memory device according to claim 13 , wherein the seventh blocking layer is disposed between the channel layer and the sixth blocking layer.
15. The ferroelectric memory device according to claim 1 , wherein the source/drain electrodes are embedded in the channel layer.
16. A ferroelectric memory device, comprising:
a gate electrode;
a channel layer, disposed at a side of the gate electrode;
a ferroelectric layer, extending between the gate electrode and the channel layer;
a blocking layer, sandwiched between the ferroelectric layer and the channel layer, wherein the blocking layer and the channel layer comprise a same material and the blocking layer is further incorporated with nitrogen, or the blocking layer and the ferroelectric layer comprise a same material and the blocking layer is further incorporated with nitrogen; and
source/drain electrodes, disposed at opposite sides of the gate electrode, and electrically connected to the channel layer.
17. The ferroelectric memory device according to claim 16 , wherein the blocking layer is in direct contact with the channel layer when the blocking layer and the channel layer comprise the same material, and is in direct contact with the ferroelectric layer when the blocking layer and the channel layer comprise the same material.
18. A semiconductor chip, comprising:
a semiconductor substrate;
active devices, formed on the semiconductor substrate;
interconnections, extending over the active devices and electrically connected to the active devices;
a memory array, disposed over the interconnections, and comprising ferroelectric memory devices respectively comprising:
a gate electrode;
a ferroelectric layer, disposed at a side of the gate electrode;
a channel layer, capacitively coupled to the gate electrode through the ferroelectric layer;
a first blocking layer and a second blocking layer, disposed between the ferroelectric layer and the channel layer, wherein the first and second blocking layers comprise a same material, and the second blocking layer is further incorporated with nitrogen; and
source/drain electrodes, disposed at opposite sides of the gate electrode, and electrically connected to the channel layer.
19. The semiconductor chip according to claim 18 , wherein the ferroelectric memory devices are arranged at a same horizontal level.
20. The semiconductor chip according to claim 18 , wherein the ferroelectric memory devices are arranged as multiple stacks.