Non-volatile memory device having phase-change material and method for fabricating the same
A non-volatile memory device includes a plurality of memory blocks. Each of memory blocks includes a main area including a plurality of first memory cells having a phase-change material and a spare area including at least one second memory cell for storing initial information about the plurality of first memory cells. In the non-volatile memory device, a circuit of the at least one second memory cell is cut off according to the initial information, and the initial information is defective block information that is information about a defect of the plurality of memory blocks.
1. A non-volatile memory device, comprising:
a plurality of memory blocks, each comprising:
a main area including a plurality of first memory cells having a phase-change material; and
a spare area including at least one second memory cell for storing initial information about the plurality of first memory cells,
wherein a circuit of the at least one second memory cell is cut off according to the initial information, and the initial information is defective block information that is information about a defect of the plurality of memory blocks, and
wherein the at least one second memory cell comprises:
a phase-change element connected to a bit line;
a switching element opening and closing a connection between the phase-change element and ground according to a signal applied via a word line; and
a fuse layer that is opened by an electromagnetic wave, and
wherein the fuse layer is arranged between the bit line and the phase-change element, between the phase-change element and the switching element, or between the switching element and the ground.
2. The non-volatile memory device of claim 1 , wherein, in a read operation, the at least one second memory cell is unchangedly read as the same logic value.
3. The non-volatile memory device of claim 1 , wherein the at least one second memory cell is provided in plural, each second memory cell comprises a phase-change element connected to a bit line and a transistor element that opens and closes a connection between the phase-change element and ground according to a signal applied via a word line, and the word line that is commonly connected to gates of the plurality of transistor elements is floated by cutting when a block including the plurality of second memory cells is defective.
4. The non-volatile memory device of claim 1 , wherein the at least one second memory cell comprises a phase-change element and a diode element serially connected between a bit line and a word line, and a fuse layer that is opened by an electromagnetic wave and arranged between the bit line and the phase-change element or between the phase-change element and the diode element.
5. The non-volatile memory device of claim 1 , wherein the at least one second memory cell is provided in plural, each second memory cell comprises a phase-change element and a diode element that are serially connected to a bit line and a word line, and the word line that is commonly connected to gates of the plurality of diode elements is floated by cutting when a block including the plurality of second memory cells is defective.
6. The non-volatile memory device of claim 1 , wherein the at least one second memory cell comprises:
a contact plug arranged on a substrate;
a fuse layer arranged on the contact plug;
a lower electrode arranged on the fuse layer;
a phase-change material layer arranged on the lower electrode; and
an upper electrode arranged on the phase-change material layer.
7. The non-volatile memory device of claim 6 , wherein the lower electrode has a cross-section of a trapezoid having a lower side shorter than an upper side.
8. The non-volatile memory device of claim 1 , wherein the at least one second memory cell comprises:
a ground contact plug arranged on a substrate; and
a fuse layer arranged on the ground contact plug,
wherein the ground contact plug is connected to ground via the fuse layer.
9. The non-volatile memory device of claim 1 , wherein the at least one second memory cell comprises:
a contact plug arranged on a substrate;
a lower electrode arranged on the contact plug;
a phase-change material layer arranged on the lower electrode;
an upper electrode arranged on the phase-change material layer; and
a fuse layer arranged on the upper electrode.
10. The non-volatile memory device of claim 1 , wherein the at least one second memory cell comprises:
a word line arranged on a substrate;
an n-type semiconductor layer arranged on the word line;
a p-type semiconductor layer arranged on the n-type semiconductor layer;
a contact plug arranged on the p-type semiconductor layer;
a fuse layer arranged on the contact plug;
a lower electrode arranged on the fuse layer;
a phase-change material layer arranged on the lower electrode; and
an upper electrode arranged on the phase-change material layer.
11. The non-volatile memory device of claim 1 , wherein the at least one second memory cell comprises:
a word line arranged on a substrate;
an n-type semiconductor layer arranged on the word line;
a p-type semiconductor layer arranged on the n-type semiconductor layer;
a contact plug arranged on the p-type semiconductor layer;
a lower electrode arranged on the contact plug;
a phase-change material layer arranged on the lower electrode;
an upper electrode arranged on the phase-change material layer; and
a fuse layer arranged on the upper electrode.