Shared bit line cross-point memory array incorporating P/N junctions
View Patent ↗A shared bit line cross-point memory array structure is provided, along with methods of manufacture. The memory structure comprises a bottom word line with a top word line overlying the bottom word line. A bit line is interposed between the bottom word line and the top word line such that a first cross-point is formed between the bottom word line and the bit line and a second cross-point is formed between the bit line and the top word line. A resistive memory material is provided at each cross-point above and below the bit line. A diode is formed at each cross-point between the resistive memory material and either the top word line or the bottom word line, respectively.
1. A memory structure comprising:
a) a substrate;
b) a plurality of doped lines overlying the substrate and isolated from each other by shallow trench isolation;
c) a plurality of bit electrodes overlying the doped bit lines at an angle, whereby a cross-point is formed at each location where a bit electrode crosses a doped bit line;
d) a plurality of diodes comprising the doped lines and a doped region of opposite polarity in contact with the doped lines, with each doped region located at a cross-point;
e) a plurality of bottom electrodes overlying the plurality of diodes;
f) a resistive memory active layer interposed between the plurality of bit electrodes and the plurality of bottom electrodes;
g) a second resistive memory active layer overlying the plurality of bit electrodes;
h) a plurality of stacked electrodes overlying the second resistive memory active layer; and
i) a plurality of top electrodes overlying the stacked electrodes to form a cross-point array with the plurality of bit electrodes.
2. The memory structure of claim 1 , wherein the doped lines are n-type lines.
3. The memory structure of claim 1 , wherein the doped lines are n-type word lines and each doped region is a p-type region.
4. The memory structure of claim 1 , wherein the plurality of bit lines further comprise bit lines that are isolated from each other by an insulating material.
5. The memory structure of claim 1 , wherein the plurality of bit lines further comprise bit lines that are separated from each other by a resistive memory material.
6. The memory structure of claim 1 , wherein the bottom electrodes are platinum, iridium, or ruthenium.
7. The memory structure of claim 1 , wherein the resistive memory active layer is a perovskite material.
8. The memory structure of claim 1 , wherein the resistive memory active layer is a colossal magnetoresistance (CMR) material.
9. The memory structure of claim 1 , wherein the resistive memory active layer is Pr 0.7 Ca 0.3 MnO 3 (PCMO).
10. The memory structure of claim 1 , wherein the resistive memory active layer is Gd 0.7 Ca 0.3 BaCo 2 O 5+5 .
11. The memory structure of claim 1 , wherein the plurality of stacked electrodes comprises n+ polysilicon/p+ polysilicon/metal stacks.
12. The memory structure of claim 11 , wherein the n+ polysilicon/p+ polysilicon/metal stacks further comprise a barrier layer interposed between the p+ polysilicon and the metal, whereby n+ polysilicon/p+ polysilicon/barrier/metal stacks.
13. The memory structure of claim 1 , wherein the resistive memory active layer is continuous, whereby it crosses over multiple cross-points.