# US 10,312,288 B2 · Switching element, semiconductor device, and semiconductor device manufacturing method

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- Number: US 10,312,288 B2
- Document ID: US10312288B2
- Status: Granted
- Kind: B2
- Application number: 15/561,586
- Filed: 2016-04-06
- Published: 2018-03-01
- Granted: 2019-06-04
- Earliest claimed: 2015-04-06
- Assignees: NEC Corporation
- Applicants: NEC Corporation
- Inventors: Munehiro Tada; Tadahiko Sugibayashi
- Web page: https://patentgrep.com/patent/US10312288B2

## CPC

- H10B 63/32: {of the bipolar type}
- H10B 63/00: Resistance change memory devices, e.g. resistive RAM [ReRAM] devices
- H10B 63/20: {comprising selection components having two electrodes, e.g. diodes}
- H10B 63/82: {the switching components having a common active material layer}
- H10N 70/011: {Manufacture or treatment of multistable switching devices}
- H10N 70/063: {by etching of pre-deposited switching material layers, e.g. lithography}
- H10N 70/066: {by filling of openings, e.g. damascene method}
- H10N 70/245: {the species being metal cations, e.g. programmable metallization cells}
- H10N 70/826: {adapted for essentially vertical current flow, e.g. sandwich or pillar type devices}
- H10N 70/8416: {adapted for supplying ionic species}
- H10N 70/883: {Oxides or nitrides}
- H10N 70/8833: {Binary metal oxides, e.g. TaOx}
- G11C 13/0007: {comprising metal oxide memory material, e.g. perovskites}
- G11C 13/003: {Cell access}
- G11C 13/0035: {Evaluating degradation, retention or wearout, e.g. by counting writing cycles}
- G11C 13/0069: {Writing or programming circuits or methods}
- G11C 2013/009: {Write using potential difference applied between cell electrodes}
- G11C 2213/15: Current-voltage curve
- G11C 2213/72: Array wherein the access device being a diode
- G11C 2213/78: Array wherein the memory cells of a group share an access device, all the memory cells of the group having a common electrode and the access device being not part of a word line or a bit line driver
- H10B: ELECTRONIC MEMORY DEVICES
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- G11C: STATIC STORES (semiconductor memory devices H10B)

## Abstract

In the cases of performing programming by forming a two-terminal-type variable resistance element on a semiconductor device, it has been difficult to control the programming, and malfunctions have often occurred. This switching element includes at least a first variable resistance element, a second variable resistance element, a first rectifying element, and a second rectifying element, one end of the first variable resistance element and one end of the second variable resistance element are respectively connected to one end of the first rectifying element and one end of the second rectifying element, and each of the rectifying elements has two terminals.

## Claims

### Claim 1

A switching element comprising: a first variable-resistance element, a second variable-resistance element, a first rectifying element, and a second rectifying element, wherein
each of the first rectifying element and the second rectifying element is a two-terminal element, and
one end portion of the first variable-resistance element and one end portion of the second variable-resistance element are connected to one end portion of the first rectifying element and one end portion of the second rectifying element.

### Claim 2 (depends on 1)

The switching element according to claim 1, wherein
the switching element is to be inserted in a signal path, and
input and output are performed through unconnected terminals of the first variable-resistance element and the second variable-resistance element, and resistance states of the first variable-resistance element and the second variable-resistance element are controlled through unconnected terminals of the first rectifying element and the second rectifying element.

### Claim 3 (depends on 1)

The switching element according to claim 1, wherein
programming of the first variable-resistance element is performed through the second rectifying element, and
programming of the second variable-resistance element is performed through the first rectifying element.

### Claim 4 (depends on 1)

The switching element according to claim 1, wherein
each of the first variable-resistance element and the second variable-resistance element is a nonvolatile-type variable-resistance element including a first electrode, a second electrode, and a variable-resistance film sandwiched between the first electrode and the second electrode,
the first electrode is an active electrode supplying a metal ion,
the variable-resistance film is a layer through which a metal ion conducts, and
the second electrode is an inactive electrode.

### Claim 5 (depends on 1)

The switching element according to claim 1, wherein
the first and second rectifying elements are elements each of which including a third electrode, a fourth electrode, and a rectifying film sandwiched between the third electrode and the fourth electrode, and
the third electrode is of a same material as the fourth electrode.

### Claim 6 (depends on 1)

A crossbar switch array wherein at least two or more of the switching elements according to claim 1 are arranged in an array, and
a plurality of the switching elements share at least one wiring connected to an unconnected terminal.

### Claim 7

A semiconductor device comprising a bipolar-type variable-resistance element in a copper multilayer wiring layer on a semiconductor substrate, the bipolar-type variable-resistance element comprising a first variable-resistance element, a second variable-resistance element, a first rectifying element and a second rectifying element, and the semiconductor device comprising:
a plurality of copper wiring lines formed in the copper multilayer wiring layer, the plurality of copper wiring lines further serving as first electrodes;
an insulating barrier film formed on the plurality of copper wiring lines serving as first electrodes;
an opening formed on the insulating barrier film, the opening connecting to the copper wiring line serving as a first electrode;
a variable-resistance film formed on a plane including the opening;
a second electrode formed on the variable-resistance film; and
the first rectifying element and the second rectifying element formed on the second electrode.

### Claim 8 (depends on 7)

The semiconductor device according to claim 7, further comprising:
a third electrode as a control electrode, the third electrode being formed on the first rectifying element and the second rectifying element.

### Claim 9

A manufacturing method of a semiconductor device including a bipolar-type variable-resistance element in a copper multilayer wiring layer on a semiconductor substrate, the bipolar-type variable-resistance element comprising a first variable-resistance element, a second variable-resistance element, a first rectifying element and a second rectifying element, and the semiconductor device manufacturing method comprising:
forming an insulating barrier film on a copper wiring, the copper wiring lines further serving as a first electrode;
forming an opening on the insulating barrier film, the opening exposing the copper wiring serving as a first electrode;
forming a variable-resistance film on a surface including the opening;
forming a second electrode on the variable-resistance film;
forming the first and a second rectifying elements above the second electrode, respectively; and
forming a third electrode on the first and the second rectifying elements, respectively.

### Claim 10 (depends on 9)

The semiconductor device manufacturing method according to claim 9, wherein
formation of the variable-resistance film, the second electrode, the first and the second rectifying elements, and the third electrode is performed through:
forming a variable-resistance film, a second electrode, a rectifying element, a third electrode, and a hard mask film in this order on an entire surface including the opening;
by performing patterning treatment on the hard mask film, forming a mask region related to a region including a variable-resistance element part and a rectifying element part; and,
by continuously etching the third electrode, the first and the second rectifying elements, the second electrode, and the variable-resistance film using the mask region as a mask, forming a multi-layered structure of the variable-resistance film, the second electrode, the first and the second rectifying elements, and the third electrode.