Programmable resistive device and memory using diode as selector

• US 9,818,478 B2
• Filed: 12/09/2013
• Issued: 11/14/2017
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: Attopsemi Technology Co., Ltd.
• Original Assignee: Attopsemi Technology Co., Ltd.
• Inventors: Chung, Shine C.
• Primary Examiner(s): Tran, Anthan
• Assistant Examiner(s): Siddique, Mushfique
• Application Number:
  US14/101,125
• Publication Number:
  US 20140160830A1
• Time in Patent Office: 1,436 Days
• Field of Search: 365148
• CPC Class Codes: G11C 13/0004 comprising amorphous/crystalline phase transition cells
• CPC Class Codes: G11C 13/0007 comprising metal oxide memory material, e.g. perovskites
• CPC Class Codes: G11C 13/004 Reading or sensing circuits or methods
• CPC Class Codes: G11C 13/0069 Writing or programming circuits or methods
• CPC Class Codes: G11C 17/16 using electrically-fusible links
• CPC Class Codes: G11C 17/18 Auxiliary circuits, e.g. for writing into memory
• CPC Class Codes: G11C 2213/72 Array wherein the access device being a diode
• CPC Class Codes: G11C 2213/74 Array wherein each memory cell has more than one access device

Abstract

Building programmable resistive devices in contact holes at the crossover of a plurality of conductor lines in more than two vertical layers is disclosed. There are plurality of first conductor lines and another plurality of second conductor lines that can be substantially perpendicular to each other, though in two different vertical layers. A diode and/or a programmable resistive element can be fabricated in the contact hole between the first and second conductor lines. The programmable resistive element can be coupled to another programmable resistive device or shared between two programmable devices whose diodes conducting currents in opposite directions and/or coupled to a common conductor line. The programmable resistive memory can be configured to be programmable by applying voltages to conduct current flowing through the programmable resistive element to change its resistance for a different logic state.

Claims

1. A Programmable Resistive Device (PRD) memory, comprising:

a plurality of PRD cells, at least one of the cells comprising;

at least one PRD including at least a diode and a Programmable Resistive Element (PRE) formed in a contact hole at a crossover of first conductor lines and second conductor lines located in two or more vertical layers;

the PRE coupled to the respective first conductor line; and

the diode including at least a first active region and a second active region isolated from the first active region, where the first active region having a first type of dopant and a second active region having a second type of dopant, the first active region providing a first terminal of the diode, the second active region providing a second terminal of the diode, the first active region coupled to the PRE and the second active region coupled to the respective second conductor line,

wherein the PRE of the at least one PRD is coupled to another PRD or shared between two PRDs whose diode is coupled to the respective second conductor line or the respective third conductor line, such coupling is facilitated by an extension that extends vertically through the second conductor line penetrating into the second conductor to couple to the PRE or the diode of the another PRD, and

wherein the PRE is configured to be programmable by applying voltages to the first conductor line, the second conductor line and/or the third conductor line to thereby change its resistance for a different logic state.

2. A PRD memory as recited in claim 1, wherein the PRE includes at least one of fuse, anti-fuse, phase-change thin film, resistive RAM thin film, or Magnetic Tunnel Junction (MTJ).

3. A PRD memory as recited in claim 1, wherein the first, the second, and/or the third conductor lines have uneven spacing therebetween in at least one conductor layer.

4. A PRD memory as recited in claim 1, wherein the at least one of the cells comprises another PRD, and wherein the two diodes in the two PRDs that have the same PRE shared conduct current in opposite directions.

5. A PRD memory as recited in claim 1, wherein the PRE is an electrical fuse constructed from at least one of material that includes silicon, polysilicon, silicide, silicided silicon, silicided polysilicon, germanium, SiGe, metal, metal alloy, barrier metal, or combination thereof.

6. A PRD memory as recited in claim 5, wherein the electrical fuse is programmable by more than one voltage or current pulse with progressive resistance changes.

7. A PRD memory as recited in claim 5, wherein the PRE in the contact hole has a length to width ratio of between 1.0 and 6.

8. A PRD memory as recited in claim 1, wherein the diode has a third active region, between the first active region and the second active region, that is unintentionally doped or slightly doped.

9. A PRD memory as recited in claim 1, wherein a contact pillar is provided at the crossover between the respective first and second conductor lines, and wherein the diode or the PRE in the contact pillar is built by Chemical Vapor Deposition (CVD) with in-situ doping.

10. A PRD memory as recited in claim 1, wherein an opening of the contact hole is smaller than an opening of at least one contact hole outside of the PRD memory.

11. A PRD memory as recited in claim 1, wherein the PRD memory comprises a memory array, and wherein the space between the first, the second, and/or the third conductor lines are less than the space between first, second, and/or the third conductor lines, respectively, outside of the memory array.

12. An electronic system, comprising:

a processor; and

a programmable resistive memory operatively connected to the processor, the programmable resistive memory including a plurality of programmable resistive devices, at least one of the devices comprising;

a diode and/or a programmable resistive element being fabricated in a contact hole at the crossovers of a plurality of the first and a plurality of second conductor lines located in more than two vertical layers;

the programmable resistive element coupled to a first conductor line; and

the diode including at least a first active region and a second active region isolated from the first active region, where the first active region having a first type of dopant and the second region having a second type of dopant, the first active region providing a first terminal of the diode, the second active region providing a second terminal of the diode, the first active region coupled to the programmable resistive element, and the second active region coupled to a second conductor line,

wherein at least one of the programmable resistive element coupled to another programmable resistive device or shared between two programmable resistive devices whose diode being coupled to the second or a third conductor line, such coupling is facilitated by an extension that extends vertically through the second conductor line penetrating into the second conductor to couple to the PRE or the diode of the another PRD, and

wherein the programmable resistive element is configured to be programmable by applying voltages to at least one of the first, the second and/or the third conductor lines to thereby change the resistance for a different logic state.

13. An electronic system as recited in claim 12, wherein the programmable resistive element includes at least one of fuse, anti-fuse, phase-change thin film, resistive RAM thin film, or Magnetic Tunnel Junction (MTJ).

14. An electronic system as recited in claim 12, wherein the programmable resistive element is constructed from at least one of material that includes silicon, polysilicon, silicide, silicided silicon, silicided polysilicon, germanium, SiGe, metal, metal alloy, barrier metal, or combination thereof.

15. A method for operating a programmable resistive memory comprises:

providing a plurality of programmable resistive memory devices, at least one of the programmable resistive devices includes at least (i) a diode and/or a programmable resistive element fabricated in a contact hole at the cross-over of a plurality of the first and a plurality of second conductor lines in more than two different vertical planes;

(ii) the programmable resistive element coupled to a first conductor line;

(iii) the diode including at least a first active region and a second active region isolated from the first active region, where the first active region having a first type of dopant and the second region having a second type of dopant, the first active region providing a first terminal of the diode, the second active region providing a second terminal of the diode, the first active region coupled to the programmable resistive element, and the second active region coupled to a second conductor line; and

(iv) at least one programmable resistive element being coupled to another programmable resistive devices or shared between two programmable resistive devices whose diode being coupled to the second or a third conductor line, such coupling is facilitated by an extension that extends vertically through the second conductor line penetrating into the second conductor to couple to the PRE or the diode of the another PRD, and

programming a logic state into at least one of the programmable resistive devices by applying voltages to at least one of the first, the second, and/or the third conductor lines.

16. A method as recited in claim 15, wherein the programmable resistive element includes at least one of fuse, anti-fuse, phase-change thin film, resistive RAM thin film, or Magnetic Tunnel Junction (MTJ).

17. A method as recited in claim 15, wherein the programmable resistive element is constructed from at least one of material that includes silicon, polysilicon, silicide, silicided silicon, silicided polysilicon, germanium, SiGe, metal, metal alloy, barrier metal, or combination thereof.

18. A method as recited in claim 15, wherein the at least one of the conductor lines for the programmable resistive devices have uneven spacing between adjacent conductor lines.

19. A method as recited in claim 15, wherein the two diodes in two programmable resistive devices that share a common programmable resistive element conduct currents in opposition directions.

20. A method as recited in claim 15, wherein the diode and/or programmable resistive element is fabricated by chemical vapor deposition (CVD) with in situ doping.

21. A method as recited in claim 15, wherein the diode and programmable resistive element is fabricated partly by (i) build a bottom conductor line, (ii) deposit inter-layer dielectric and etch a contact hole, (iii) build semiconductor for diode and programmable resistive element with different dopants and doses inside the contact hole, (iv) etch the inter-layer dielectric until the programmable resistive element is exposed, (v) build silicide on the surface of the programmable resistive element, (vi) deposit inter-layer dielectric to cover the programmable resistive element, and (vii) build top conductor line to couple at least a portion of programmable resistive element by damascene process.

22. A method as recited in claim 15, wherein the at least one programmable resistive element is an electrical fuse that is programmable by a plurality of voltage or current pulses with progressive resistance changes.

23. An electronic system, comprising:

a processor; and

a programmable resistive memory operatively connected to the processor, the programmable resistive memory including a plurality of programmable resistive devices, at least one of the devices comprising;

a diode and a programmable resistive element being fabricated in a contact hole at the crossovers of at least one first conductor line and at least one second conductor line, which are located in different vertical layers;

the programmable resistive element coupled to the first conductor line; and

the diode including at least a first active region and a second active region isolated from the first active region, where the first active region having a first type of dopant and the second region having a second type of dopant, the first active region providing a first terminal of the diode, the second active region providing a second terminal of the diode, the first active region coupled to the programmable resistive element, and the second active region coupled to the second conductor line,

wherein at least one of the programmable resistive elements is coupled to another programmable resistive device via the second conductor line,

wherein the coupling of the at least one of the programmable resistive elements to another programmable resistive device is facilitated by an extension that extends vertically through the second conductor line penetrating into the second conductor to couple to the another programmable resistive device, and

wherein the programmable resistive element is configured to be programmable by applying voltages to at least one of the first conductor line and/or the second conductor line to thereby change the resistance for a different logic state.

24. An electronic system as recited in claim 23, wherein the programmable resistive element includes at least a programmable electrical fuse.

25. An electronic system as recited in claim 23, wherein programmable resistive element has a length to the contact width ratio of between 1.0 and 6.

26. An electronic system as recited in claim 23, wherein a contact pillar is provided at the crossover between the respective first and second conductor lines.

27. An electronic system as recited in claim 23, wherein an opening in of the contact hole is smaller than at least one contact hole outside of the programmable resistive memory.

28. An electronic system as recited in claim 23, wherein the extension that extends vertically through the second conductor line penetrating into the second conductor to couple to the diode of the another programmable resistive device.