IP Library Granted Patent US 7,528,405
Granted Patent B2
US 7,528,405 · App. 11/714,555 · Granted May 5, 2009

Conductive memory stack with sidewall

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Quick Facts
Patent No.
US 7,528,405
App. No.
11/714,555
Granted
May 5, 2009
Kind
B2
Abstract

A conductive memory stack is provided. The memory stack includes a bottom electrode, a top electrode and a multi-resistive state element. The multi-resistive state element is sandwiched between the electrodes such that the top face of the bottom electrode is in contact with the multi-resistive state element's bottom face and the bottom face of the top electrode is in contact with the multi-resistive state element's top face. The bottom electrode, the top electrode and the multi-resistive state element all have sides that are adjacent to their faces. Furthermore, the sides are at least partially covered by a sidewall layer.

Claims (31)

1. A conductive memory device comprising:

a bottom electrode including a top face;

a top electrode located above the bottom electrode and including a bottom face having a second surface area; and

a multi-resistive state element sandwiched between the bottom electrode and the top electrode and including a bottom face and a top face, the top face having a fourth surface area, the second surface area is smaller than the fourth surface area,

the multi-resistive state element's bottom face being in contact with the bottom electrode's top face, the multi-resistive state element's top face being in contact with the top electrode's bottom face,

wherein the bottom electrode, the top electrode and the multi-resistive state element each have sides that are adjacent to their faces, and

wherein the sides are at least partially covered by a sidewall layer.

2. The conductive memory device of claim 1 , wherein the multi-resistive state element comprises a conductive metal oxide (CMO).

3. The conductive memory device of claim 2 , wherein the CMO comprises a perovskite.

4. The conductive memory device of claim 1 , wherein the multi-resistive state element comprises a two-terminal memory element.

5. The conductive memory device of claim 4 , wherein the two-terminal memory element is configured in a cross point memory array including at least one layer of memory.

6. A conductive memory device comprising:

a bottom electrode including a top face;

a top electrode located above the bottom electrode and including a bottom face having a second surface area;

a hard mask layer including a bottom face with a surface area substantially similar to the second surface area, the top electrode including a top face that is in contact with the bottom face of the hard mask layer; and

a multi-resistive state element sandwiched between the bottom electrode and the top electrode and including a bottom face and a top face, the top face having a fourth surface area, the second surface area is smaller than the fourth surface area,

the multi-resistive state element's bottom face being in contact with the bottom electrode's top face, the multi-resistive state element's top face being in contact with the top electrode's bottom face,

wherein the bottom electrode, the top electrode and the multi-resistive state element each have sides that are adjacent to their faces, and

wherein the sides are at least partially covered by a sidewall layer.

7. The conductive memory device of claim 6 , wherein the multi-resistive state element comprises a conductive metal oxide (CMO).

8. The conductive memory device of claim 7 , wherein the CMO comprises a perovskite.

9. The conductive memory device of claim 6 , wherein the multi-resistive state element comprises a two-terminal memory element.

10. The conductive memory device of claim 9 , wherein the two-terminal memory element is configured in a cross point memory array including at least one layer of memory.

11. A conductive memory device comprising:

a bottom electrode including a top face;

a top electrode located above the bottom electrode and including a bottom face; and

a multi-resistive state element sandwiched between the bottom electrode and the top electrode and including a bottom face and a top face, the multi-resistive state element's bottom face being in contact with the bottom electrode's top face, and the multi-resistive state element's top face being in contact with the top electrode's bottom face,

the bottom electrode's top face has a first surface area, the top electrode's bottom face has a second surface area, the multi-resistive state element's bottom face has a third surface area, the multi-resistive state element's top face has a fourth surface area, the first second, third and fourth surface areas are approximately equal,

the bottom electrode's top face, the top electrodes bottom face, the multi-resistive state element's bottom face, and the multi-resistive state element's top face are substantially aligned, thereby all the faces have the same footprint,

wherein the bottom electrode, the top electrode and the multi-resistive state element each have sides that are adjacent to their faces and the sides are at least partially covered by a sidewall layer, and

wherein the multi-resistive state element comprises a two-terminal memory element configured in a cross point memory array including at least one layer of memory.

Assignments (4)
RELEASE Recorded Apr 9, 2012
From: SILICON VALLEY BANK; GOLD HILL CAPITAL
To: UNITY SEMICONDUCTOR, INC.
Reel/Frame 028132/0675 →
CORRECTIVE ASSIGNMENT TO CORRECT THE CORRECTIVE ASSIGNMENT TO DELETE ASSIGNOR WAYNE KINNEY AS AN INVENTOR AND TO DELETE ASSIGNOR EDMOND R. WARD AS AN INVENTOR PREVIOUSLY RECORDED ON REEL 020250 FRAME 0636. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded May 7, 2009
From: RINERSON, DARRELL; CHEVALLIER, CHRISTOPHE J.; HSIA, STEVE KUO-REN
To: UNITY SEMICONDUCTOR CORPORATION
Reel/Frame 022645/0558 →
SECURITY AGREEMENT Recorded Apr 13, 2009
From: UNITY SEMICONDUCTOR CORPORATION
To: GOLD HILL CAPITAL
Reel/Frame 023129/0669 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 14, 2007
From: RINERSON, DARRELL, MR.; CHEVALLIER, CHRISTOPHE, MR.; HSIA, STEVE KUO-REN; KINNEY, WAYNE; LONGCOR, STEVEN W.; WARD, EDMOND R.
To: UNITY SEMICONDUCTOR CORPORATION
Reel/Frame 020250/0636 →