Method of making 3D R/W cell with reduced reverse leakage

• US 7,800,939 B2
• Filed: 06/29/2007
• Issued: 09/21/2010
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk 3D LLC (Western Digital Corporation)
• Inventors: Petti, Christopher J., Kumar, Tanmay
• Primary Examiner(s): Le; Vu A
• Assistant Examiner(s): Yang; Han
• Application Number:
  US11/819,895
• Publication Number:
  US 20090003036A1
• Time in Patent Office: 1,180 Days
• Field of Search: 365/148, 365/158, 365/171, 365/163, 365/48, 365/1
• US Class Current: 365/163
• CPC Class Codes: G11C 13/00 Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
• CPC Class Codes: G11C 13/0069 Writing or programming circuits or methods
• CPC Class Codes: G11C 2013/009 Write using potential difference applied between cell electrodes
• CPC Class Codes: G11C 2213/72 Array wherein the access device being a diode
• CPC Class Codes: H01L 27/101 including resistors or capacitors only
• CPC Class Codes: H01L 27/1021 including diodes only
• CPC Class Codes: H10B 63/00 Resistance change memory devices, e.g. resistive RAM [ReRAM] devices

Abstract

A method of making a nonvolatile memory device includes forming a semiconductor diode steering element, and forming a semiconductor read/write switching element.

Claims

1. A method of operating a nonvolatile memory device, comprising:

providing a non-volatile memory cell comprising a semiconductor diode steering element, a semiconductor read/write switching element, and at least one conductive layer located between the steering element and the, and a crystallization template layer which directly physically contacts the steering element but does not contact the read/write switching element, wherein the crystallization template layer comprises a C49 phase crystallization template material selected from the group consisting of titanium silicide, titanium germanide or titanium silicide-germanide read/write switching element;

first switching the read/write switching element from a first resistivity state to a second resistivity state different from the first resistivity state; and

second switching the read/write switching element from the second resistivity state to the first resistivity state.

2. The method of claim 1, wherein the first and the second steps of switching comprise applying a first and a second electrical pulse, respectively, to the steering element and to the read/write switching element.

3. The method of claim 2, wherein steering element does not switch from the first resistivity state to the second resistivity state in response to the first and the second applied electrical pulses.

4. The method of claim 3, wherein:

the steering element is formed in a low resistivity state which does not change in response to the first and the second applied electrical pulses;

the read/write switching element is formed in a high resistivity state which changes in response to the first and the second applied electrical pulses; and

the first and the second electrical pulses comprise forward bias electrical pulses of a different magnitude from each other.

5. The method of claim 1, wherein the read/write switching element comprises a resistor.

6. The method of claim 1, wherein:

the read/write switching element consists essentially of amorphous, polycrystalline or a combination amorphous and polycrystalline Group IV semiconductor resistor; and

the steering element comprises a crystallized polycrystalline Group IV semiconductor diode.

7. The method of claim 1, wherein the at least one conductive layer comprises metal, metal silicide or titanium nitride.

8. The method of claim 1, wherein the read/write switching element, the silicide crystallization template layer, the at least one conductive layer and the steering element have a shape of a vertical pillar, wherein the vertical pillar is located between a first electrode and a second electrode.