U.S. patent application number 16/774322 was filed with the patent office on 2021-04-29 for logic device using spin torque.
This patent application is currently assigned to KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY. The applicant listed for this patent is KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY. Invention is credited to Dong Soo Han, Seok Min Hong, Hyung Jun Kim, Kyoung Whan Kim, Hyun Cheol Koo, Ouk Jae Lee, Byoung Chul Min, Tae Eon Park.
Application Number | 20210126639 16/774322 |
Document ID | / |
Family ID | 1000004640071 |
Filed Date | 2021-04-29 |
United States Patent
Application |
20210126639 |
Kind Code |
A1 |
Kim; Kyoung Whan ; et
al. |
April 29, 2021 |
LOGIC DEVICE USING SPIN TORQUE
Abstract
A logic function device according to an embodiment of the
present invention includes one or more function reconfiguring units
having magnetization in one direction set by spin torque caused due
to an function reconfiguring current, and an output terminal formed
at an end thereof; and one or more input units formed on the
function reconfiguring unit and having magnetization in the one
direction set by spin torque caused due to an input current,
wherein an output voltage of the output terminal is determined on
the basis of whether a magnetization direction of the function
reconfiguring unit and a magnetization direction of the input unit
are parallel or anti-parallel.
Inventors: |
Kim; Kyoung Whan; (Seoul,
KR) ; Han; Dong Soo; (Seoul, KR) ; Min; Byoung
Chul; (Seoul, KR) ; Hong; Seok Min; (Seoul,
KR) ; Koo; Hyun Cheol; (Seoul, KR) ; Kim;
Hyung Jun; (Seoul, KR) ; Park; Tae Eon;
(Seoul, KR) ; Lee; Ouk Jae; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY |
Seoul |
|
KR |
|
|
Assignee: |
KOREA INSTITUTE OF SCIENCE AND
TECHNOLOGY
Seoul
KR
|
Family ID: |
1000004640071 |
Appl. No.: |
16/774322 |
Filed: |
January 28, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11C 11/161 20130101;
H03K 19/20 20130101; G11C 11/1675 20130101; H03K 19/16
20130101 |
International
Class: |
H03K 19/16 20060101
H03K019/16; G11C 11/16 20060101 G11C011/16; H03K 19/20 20060101
H03K019/20 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2019 |
KR |
10-2019-0132010 |
Claims
1. A logic function device, comprising: one function reconfiguring
unit having magnetization in one direction set by spin torque
caused due to a function reconfiguring current, and having an
output terminal; and one input unit formed on the function
reconfiguring unit and having magnetization in the one direction
set by spin torque caused due to an input current, wherein an
output voltage of the output terminal is determined on the basis of
whether a magnetization direction of the function reconfiguring
unit and a magnetization direction of the input unit are parallel
or anti-parallel, a value (V.sub.P) of the output voltage when the
magnetization direction of the function reconfiguring unit and the
magnetization direction of the input unit are parallel, is greater
than a value (Vap) of the output voltage when the magnetization
direction of the function reconfiguring unit and the magnetization
direction of the input unit are anti-parallel; and the output value
is set to "1" when the value of the output voltage is V.sub.P, and
the output value is set to "0" when the value of the output voltage
is Vap, to perform a NOT logic operations.
2. The device of claim 1, wherein the magnetization directions of
the function reconfiguring unit and the input unit are any one of a
vertical direction and a horizontal direction.
3. The device of claim 1, wherein the function reconfiguring unit
includes: a function reconfiguring electrode layer through which
the function reconfiguring current flows; and a function
reconfiguring magnetic layer formed on the function reconfiguring
electrode layer and having magnetization in one direction set by
the function reconfiguring current, wherein the output terminal is
formed in the function reconfiguring electrode layer.
4. The device of claim 1, wherein the input unit includes: an input
magnetic layer formed on the function reconfiguring unit and having
magnetization in the one direction; and an input electrode layer
formed on the input magnetic layer and through which the input
current flows to manipulate the magnetization of the input magnetic
layer.
5. (canceled)
6. A logic function device, comprising: one or more function
reconfiguring units having magnetization in one direction set by
spin torque caused due to a function reconfiguring current, and
having an output terminal; and one or more input units formed on
the function reconfiguring unit and having magnetization in the one
direction set by spin torque caused due to an input current,
wherein an output voltage of the output terminal is determined on
the basis of whether a magnetization direction of the function
reconfiguring unit and a magnetization direction of the input unit
are parallel or anti-parallel, wherein the number of function
reconfiguring units is one; the number of input units is multiple
and horizontally arranged on the function reconfiguring unit; and
the magnetization direction of the function reconfiguring unit is
set to be the same for the multiple input units.
7. The device of claim 6, wherein the input unit includes a first
input unit and a second input unit; one terminal of the function
reconfiguring unit located on the first input unit is connected to
a ground voltage, and the output terminal is horizontally opposite
to the one terminal of the function reconfiguring unit and located
on the second input unit; and a maximum value (V.sub.max) of the
output voltage when the magnetization direction of the first input
unit and the magnetization direction of the function reconfiguring
unit are parallel, and the magnetization direction of the second
input unit and the magnetization direction of the function
reconfiguring unit are parallel, a first value (V.sub.1) of the
output voltage when the magnetization direction of the first input
unit and the magnetization direction of the function reconfiguring
unit are anti-parallel, and the magnetization direction of the
second input unit and the magnetization direction of the function
reconfiguring unit are parallel, a second value (V.sub.2) of the
output voltage when the magnetization direction of the first input
unit and the magnetization direction of the function reconfiguring
unit are parallel, and the magnetization direction of the second
input unit and the magnetization direction of the function
reconfiguring unit are anti-parallel, and a minimum value
(V.sub.min) of the output voltage when the magnetization direction
of the first input unit and the magnetization direction of the
function reconfiguring unit are anti-parallel, and the
magnetization direction of the second input unit and the
magnetization direction of the function reconfiguring unit are
anti-parallel satisfy the following relationship:
V.sub.max>V.sub.1>V.sub.2>V.sub.min.
8. The device of claim 7, wherein the magnetization direction of
the function reconfiguring unit is an up direction; a reference
voltage (Vref) is set between the maximum value (V.sub.max) of the
output voltage and the first value (V.sub.1) of the output voltage;
and the output value is set to "1" when the output voltage is
greater than the reference voltage, and the output value is set to
"0" when the output voltage is less than the reference voltage,
thereby performing an AND logic operation.
9. The device of claim 7, wherein the magnetization direction of
the function reconfiguring unit is an up direction; a reference
voltage (Vref) is set between the second value (V.sub.2) of the
output voltage and the minimum value (V.sub.min) of the output
voltage; and the output value is set to "1" when the output voltage
is greater than the reference voltage, and the output value is set
to "0" when the output voltage is less than the reference voltage,
thereby performing an OR logic operation.
10. The device of claim 7, wherein the magnetization direction of
the function reconfiguring unit is a down direction; a reference
voltage (Vref) is set between the maximum value (V.sub.max) of the
output voltage and the first value (V.sub.1) of the output voltage;
and the output value is set to "1" when the output voltage is
greater than the reference voltage, and the output value is set to
"0" when the output voltage is less than the reference voltage,
thereby performing a NOR logic operation.
11. The device of claim 7, wherein the magnetization direction of
the function reconfiguring unit is a down direction; a reference
voltage (Vref) is set between the second value (V.sub.2) of the
output voltage and the minimum value (V.sub.min) of the output
voltage; and the output value is set to "1" when the output voltage
is greater than the reference voltage, and the output value is set
to "0" when the output voltage is less than the reference voltage,
thereby performing a NAND logic operation.
12. The device of claim 6, wherein the input unit includes a third
input unit, a fourth input unit, and a fifth input unit; and one
terminal of the function reconfiguring unit located on the third
input unit is connected to a ground voltage, and the output
terminal is horizontally opposite to the one terminal of the
function reconfiguring unit and located on the fifth input unit
side, thereby performing a ternary logic operation.
13. The device of claim 12, wherein the magnetization direction of
the function reconfiguring unit is an up direction; a reference
voltage is set between a value of the output voltage when the
magnetization direction of the third input unit and the
magnetization direction of the function reconfiguring unit are
parallel, the magnetization direction of the fourth input unit and
the magnetization direction of the function reconfiguring unit are
parallel, and the magnetization direction of the fifth input unit
and the magnetization direction of the function reconfiguring unit
are parallel, and a value of the output voltage when the
magnetization direction of the third input unit and the
magnetization direction of the function reconfiguring unit are
anti-parallel, the magnetization direction of the fourth input unit
and the magnetization direction of the function reconfiguring unit
are parallel, and the magnetization direction of the fifth input
unit and the magnetization direction of the function reconfiguring
unit are parallel; and the output value is set to "1" when the
output voltage is greater than the reference voltage, and the
output value is set to "0" when the output voltage is less than the
reference voltage, thereby performing a ternary AND logic
operation.
14. A logic function device, comprising: one or more function
reconfiguring units having magnetization in one direction set by
spin torque caused due to a function reconfiguring current, and
having an output terminal; and one or more input units formed on
the function reconfiguring unit and having magnetization in the one
direction set by spin torque caused due to an input current,
wherein an output voltage of the output terminal is determined on
the basis of whether a magnetization direction of the function
reconfiguring unit and a magnetization direction of the input unit
are parallel or anti-parallel, wherein the one or more function
reconfiguring units and the one or more input units are each
horizontally arranged, and the function reconfiguring unit and the
input unit are formed to vertically correspond to each other; and
the magnetization directions of the one or more function
reconfiguring units are set independently of each other.
15. The device of claim 14, wherein the one or more function
reconfiguring units include: a function reconfiguring electrode
layer through which the function reconfiguring current flows; and
multiple function reconfiguring magnetic layers horizontally formed
on the function reconfiguring electrode layer at a predetermined
interval and having magnetization in the one direction set by the
function reconfiguring current, wherein a part of the multiple
function reconfiguring magnetic layers to which a voltage is
applied in the one direction and a remainder of the function
reconfiguring magnetic layers to which the voltage is not applied
have magnetic anisotropy different from each other, and the
magnetization directions of the part of a multiple reset magnetic
layers and the remainder of the function reconfiguring magnetic
layers are set opposite to each other by the function reconfiguring
current.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent
Application No. 10-2019-0132010, filed Oct. 23, 2019, the entire
contents of which is incorporated herein for all purposes by this
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a logic function device
using spin torque and, more particularly, to a logic device that is
capable of reconfiguring the logic function through electrical
signals in the same structure.
Description of the Related Art
[0003] A logic device, which performs logic operations in
integrated circuits, is one of high added value products along with
a memory device. However, recently, as silicon-based electronic
device technology (complementary metal-oxide semiconductor, CMOS)
is approaching physical limitations, it is difficult to expect
further density improvement, and problems such as high power
consumption and heat generation are also caused. Accordingly, it is
required to develop next-generation logic devices with new
mechanisms, escaping from CMOS-based technologies in the related
art.
[0004] Since a nano-spin device using a magnetic material is
characterized by having non-volatility and is capable of low-power
and ultra-fast information control, the nano-spin device is one of
the promising candidate technologies as the next generation
information processing device. In particular, the non-volatility of
the spin element cuts off the unnecessary power supply of the
circuit every logic operation, whereby there are advantages that
standby power is lowered and high-efficiency logic operations
capable of being operated at low power consumption are possible.
Furthermore, a reset function and high speed operation are
improved.
[0005] The basic driving principle of the spin device is to control
the spin that is an intrinsic physical quantity of electrons, by an
electrical signal. The spin device is required to control the
magnetization direction in the magnetic layer through the
electrical signal to write the information efficiently and quickly,
and accurately read the magnetic information. To this end, as
representative technologies, the spin device typically uses a
spin-torque technology including spin-transfer torque (STT) and
spin-orbit torque (SOT) for magnetization switching, and the
magnetoresistance effect, such as giant magnetoresistance (GMR),
tunneling magnetoresistance (TMR), and the like for reading
magnetization information in a magnetic layer.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the related art, and an
objective of the present invention is to provide an reconfigurable
logic device that is capable of electrically resetting a logic
function in the same device, in order to fundamentally overcome
physical limitations of existing silicon devices by using spin
torque technology.
[0007] However, the object is exemplary, and the scope of the
present invention is not limited thereto, and embodiments according
to the present invention may be used to achieve other objects not
specifically mentioned in addition to the above objects.
[0008] A logic function device according to an embodiment of the
present invention includes: one or more function reconfiguring
units having magnetization in one direction set by spin torque
caused due to a function reconfiguring current, and an output
terminal formed at an end thereof; and one or more input units
formed on the function reconfiguring unit and having magnetization
in the one direction set by spin torque caused due to an input
current, wherein an output voltage of the output terminal is
determined on the basis of whether a magnetization direction of the
function reconfiguring unit and a magnetization direction of the
input unit are parallel or anti-parallel.
[0009] The magnetization directions of the function reconfiguring
unit and the input unit may be any one of a vertical direction and
a horizontal direction.
[0010] The function reconfiguring unit may include: a function
reconfiguring electrode layer through which the function
reconfiguring current flows; and a function reconfiguring magnetic
layer formed on the function reconfiguring electrode layer and
having magnetization in one direction set by the function
reconfiguring current, wherein the output terminal is formed in the
function reconfiguring electrode layer.
[0011] The input unit may include: an input magnetic layer formed
on the function reconfiguring unit and having magnetization in the
one direction; and an input electrode layer formed on the input
magnetic layer and through which the input current flows to
manipulate the magnetization of the input magnetic layer;
[0012] The number of the function reconfiguring units may be one;
the number of the input units may be one;
[0013] a value (V.sub.P) of the output voltage when the
magnetization direction of the function reconfiguring unit and the
magnetization direction of the input unit are parallel, is greater
than a value (Vap) of the output voltage when the magnetization
direction of the function reconfiguring unit and the magnetization
direction of the input unit are anti-parallel; and the output value
is set to "1" when the value of the output voltage is V.sub.P, and
the output value is set to "0" when the value of the output voltage
is Vap, to perform a NOT logic operation.
[0014] The number of function reconfiguring units may be one; the
number of input units may be multiple and horizontally arranged on
the function reconfiguring unit; and the magnetization direction of
the function reconfiguring unit may be set to be the same for the
multiple input units.
[0015] The input unit may include a first input unit and a second
input unit; one terminal of the function reconfiguring unit located
on the first input unit may be connected to a ground voltage, and
the output terminal may be horizontally opposite to the one
terminal of the function reconfiguring unit and located on the
second input unit; a maximum value (V.sub.max) of the output
voltage when the magnetization direction of the first input unit
and the magnetization direction of the function reconfiguring unit
are parallel, and the magnetization direction of the second input
unit the magnetization direction of the function reconfiguring unit
are parallel, a first value (V.sub.1) of the output voltage when
the magnetization direction of the first input unit and the
magnetization direction of the function reconfiguring unit are
anti-parallel, and the magnetization direction of the second input
unit and the magnetization direction of the function reconfiguring
unit are parallel, a second value (V.sub.2) of the output voltage
when the magnetization direction of the first input unit and the
magnetization direction of the function reconfiguring unit are
parallel, and the magnetization direction of the second input unit
and the magnetization direction of the function reconfiguring unit
are anti-parallel, and a minimum value (V.sub.min) of the output
voltage when the magnetization direction of the first input unit
and the magnetization direction of the function reconfiguring unit
are anti-parallel, and the magnetization direction of the second
input unit and the magnetization direction of the function
reconfiguring unit are anti-parallel may satisfy the following
relationship:
V.sub.max>V.sub.1>V.sub.2>V.sub.min.
[0016] The magnetization direction of the function reconfiguring
unit may be an up direction; a reference voltage (Vref) may be set
between the maximum value (V.sub.max) of the output voltage and the
first value (V.sub.1) of the output voltage; and the output value
may be set to "1" when the output voltage is greater than the
reference voltage, and the output value is set to "0" when the
output voltage is less than the reference voltage, thereby
performing an AND logic operation.
[0017] The magnetization direction of the function reconfiguring
unit may be an up direction; a reference voltage (Vref) may be set
between the second value (V.sub.2) of the output voltage and the
minimum value (V.sub.min) of the output voltage; and the output
value may be set to "1" when the output voltage is greater than the
reference voltage, and the output value may be set to "0" when the
output voltage is less than the reference voltage, thereby
performing an OR logic operation.
[0018] The magnetization direction of the function reconfiguring
unit may be a down direction; a reference voltage (Vref) may be set
between the maximum value (V.sub.max) of the output voltage and the
first value (V.sub.1) of the output voltage; and the output value
may be set to "1" when the output voltage is greater than the
reference voltage, and the output value is set to "0" when the
output voltage is less than the reference voltage, thereby
performing a NOR logic operation.
[0019] The magnetization direction of the function reconfiguring
unit may be a down direction; a reference voltage (Vref) may be set
between the second value (V.sub.2) of the output voltage and the
minimum value (V.sub.min) of the output voltage; and the output
value may be set to "1" when the output voltage is greater than the
reference voltage, and the output value is set to "0" when the
output voltage is less than the reference voltage, thereby
performing a NAND logic operation.
[0020] The input unit may include a third input unit, a fourth
input unit, and a fifth input unit; and one terminal of the
function reconfiguring unit located on the third input unit may be
connected to a ground voltage, and the output terminal may be
horizontally opposite to the one terminal of the function
reconfiguring unit and located on the fifth input unit side,
thereby performing a ternary logic operation.
[0021] The magnetization direction of the function reconfiguring
unit may be an up direction; the reference voltage is set between a
value of the output voltage when the magnetization direction of the
third input unit and the magnetization direction of the function
reconfiguring unit are parallel, the magnetization direction of the
fourth input unit and the magnetization direction of the function
reconfiguring unit are parallel, and the magnetization direction of
the fifth input unit and the magnetization direction of the
function reconfiguring unit are parallel, and a value of the output
voltage when the magnetization direction of the third input unit
and the magnetization direction of the function reconfiguring unit
are anti-parallel, the magnetization direction of the fourth input
unit and the magnetization direction of the function reconfiguring
unit are parallel, and the magnetization direction of the fifth
input unit and the magnetization direction of the function
reconfiguring unit are parallel; and the output value may be set to
"1" when the output voltage is greater than the reference voltage,
and the output value may be set to "0" when the output voltage is
less than the reference voltage, thereby performing a ternary AND
logic operation.
[0022] The one or more function reconfiguring units and the one or
more input units may be each horizontally arranged, and the
function reconfiguring unit and the input unit may be formed to
vertically correspond to each other; and the magnetization
directions of the one or more function reconfiguring units may be
set independently of each other.
[0023] The one or more function reconfiguring units may include: a
function reconfiguring electrode layer through which the function
reconfiguring current flows; and multiple function reconfiguring
magnetic layers horizontally formed on the function reconfiguring
electrode layer at a predetermined interval and having
magnetization in the one direction set by the function
reconfiguring current, wherein a part of the multiple function
reconfiguring magnetic layers to which a voltage may be applied in
the one direction and a remainder of the function reconfiguring
magnetic layers to which the voltage is not applied have magnetic
anisotropy different from each other, and the magnetization
directions of the part of the multiple reset magnetic layers and
the remainder of the function reconfiguring magnetic layers may be
set opposite to each other by the function reconfiguring
current.
[0024] According to the embodiment of the present invention, it is
possible to fundamentally overcome the physical limitations of the
silicon device in the related art.
[0025] Further, according to the embodiment of the present
invention, in addition to the input magnetic layer that receives
the input signal, a function reconfiguring magnetic layer
determining properties of logic operation is introduced and is
controlled in a nonvolatile manner, thereby resetting the logic
function in the same structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The above and other objects, features, and other advantages
of the present invention will be more clearly understood from the
following:
[0027] FIG. 1 is a cross-sectional view illustrating a logic
function device according to an embodiment of the invention;
[0028] FIGS. 2A and 2B are diagrams illustrating a spin-orbit
torque and a spin-transfer torque generated by the function
reconfiguring unit and the input unit of FIG. 1, respectively;
[0029] FIGS. 3A and 3B are diagrams illustrating resistance
according to magnetization directions of the function reconfiguring
magnetic layer 120 and the input magnetic layer 210 of FIG. 1;
[0030] FIG. 4 is a circuit diagram modeling the logic function
device 1 of FIG. 1;
[0031] FIG. 5 is a cross-sectional view illustrating a binary logic
function device according to an embodiment of the present
invention;
[0032] FIGS. 6A and 6B are cross-sectional views illustrating the
logic function device of FIG. 5 viewed from other direction;
[0033] FIG. 7 is a circuit diagram modeling the logic function
device 2 of FIG. 5;
[0034] FIG. 8 is a cross-sectional view illustrating a binary logic
function device according to an embodiment of the present
invention; and
[0035] FIG. 9 is a cross-sectional view illustrating a ternary
logic function device according to an embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] Hereinafter, embodiments of the present invention will be
described in detail with reference to the drawings.
[0037] FIG. 1 is a cross-sectional view illustrating a logic
function device according to an embodiment of the invention.
[0038] Referring to FIG. 1, the logic function device 1 includes
one or more function reconfiguring units 100 having magnetization
in one direction set by spin torque caused due to function
reconfiguring current, and an output terminal formed at an end
thereof; and at least one input unit 200 formed on the function
reconfiguring unit and having magnetization in the one direction
set by spin torque caused due to an input current, in which an
output voltage V.sub.out of the output terminal is determined on
the basis of whether the magnetization direction of the function
reconfiguring unit and the magnetization direction of the input
unit are parallel or anti-parallel. An insulating tunnel junction
300 may be formed between the function reconfiguring unit 100 and
the input unit 200.
[0039] In the present specification, the vertical direction refers
to the z direction in the drawings. In addition, the horizontal
direction means the x direction in the drawing. Spin torque means
including spin-transfer torque and spin-orbit torque. The up
direction and down direction with respect to the magnetization
direction indicate two magnetic states in the magnetic layer and
may vary according to the magnetization direction in which the
magnetic layer prefers. For example, when the vertical
magnetization is preferred, the up and down directions mean upward
and downward, respectively, and when the horizontal magnetization
is preferred, the up and down directions mean leftward and
rightward, respectively.
[0040] The magnetization directions of the function reconfiguring
unit 100 and the input unit 200 may be any one of a vertical
direction and a horizontal direction. That is, the magnetization
directions of the function reconfiguring unit 100 and the input
unit 200 may both be in the vertical direction, or the
magnetization directions of the function reconfiguring unit 100 and
the input unit 200 may both be in the horizontal direction.
[0041] Hereinafter, the case in which the magnetization directions
of the function reconfiguring unit 100 and the input unit 200 are
both in the vertical direction will be described. However, the
scope of the present invention is not limited thereto, and the
function reconfiguring unit 100 and the input unit 200 may be in
the same direction (including the opposite direction).
[0042] The function reconfiguring unit 100 has magnetization in the
vertical direction set by spin torque caused due to a function
reconfiguring current, and an output terminal formed at an end
thereof.
[0043] The function reconfiguring unit 100 includes an function
reconfiguring electrode layer 110 through which function
reconfiguring current flows; and an function reconfiguring magnetic
layer 120 formed on the function reconfiguring electrode layer 110
and having magnetization in one direction, for example, a vertical
direction, set by the function reconfiguring current, in which the
output terminal may be formed in the function reconfiguring
electrode layer 110.
[0044] The function reconfiguring current flows in the function
reconfiguring electrode layer 110, and the magnetization is
vertically in the function reconfiguring magnetic layer 120 set by
spin torque caused due to the function reconfiguring current. The
magnetization direction in the function reconfiguring magnetic
layer 120 may be in the up direction or the down direction. In FIG.
1, a vertical bi-directional arrow in the function reconfiguring
magnetic layer 120 indicates the magnetization in the up direction
and the magnetization in the down direction at the same time.
[0045] The input unit 200 is formed on the function reconfiguring
unit 100, and has magnetization in the same direction as the
function reconfiguring unit 100, for example, a vertical direction,
set by spin torque caused due to the input current.
[0046] The input unit 200 includes an input magnetic layer 210
formed on the function reconfiguring unit 100 and having
magnetization in one direction, for example, a vertical direction;
and an input electrode layer 220 formed on the input magnetic layer
210 and through which a current flows to manipulate the
magnetization in the input magnetic layer 210.
[0047] The input current flows in the input electrode layer 220,
and the magnetization is vertically in the input magnetic layer 210
set by spin torque caused due to the input current. The
magnetization direction in the input magnetic layer 210 may be in
the up direction or in the down direction. In FIG. 1, a vertical
bi-directional arrow in the input magnetic layer 210 indicates
magnetization in the up direction and magnetization in the down
direction at the same time.
[0048] An output voltage V.sub.out of the output terminal is
determined on the basis of whether the magnetization direction of
the function reconfiguring unit 100 and the magnetization direction
of the input unit 200 are parallel or anti-parallel. In this
specification, what the magnetization directions are parallel means
that both magnetization directions are the same, i.e., both are up
directions or both are down directions. What magnetization
directions are anti-parallel means that both magnetization
directions are opposite to each other, i.e., one direction is up
direction and the other direction is down direction.
[0049] A method of determining the output voltage V.sub.out of the
output terminal according to the magnetization direction of the
function reconfiguring unit 100 and the magnetization direction of
the input unit 200 will be described later.
[0050] FIG. 2A is a diagram illustrating a spin-orbit torque
generated by the function reconfiguring unit 100 and the input unit
200 of FIG. 1, and FIG. 2B is a diagram illustrating a
spin-transfer torque generated at the function reconfiguring unit
100 and the input unit 200 of FIG. 1.
[0051] In FIGS. 2A and 2B, an electrode layer 10 corresponds to the
function reconfiguring electrode layer 110 of the function
reconfiguring unit 100 or the input electrode layer 220 of the
input unit 200; a magnetic layer 20 corresponds to the function
reconfiguring magnetic layer 120 of the function reconfiguring unit
100 or the input magnetic layer 210 of the input unit 200; and the
tunnel junction layer 30 corresponds to the tunnel junction
300.
[0052] Referring to FIGS. 2A and 2B, when a current flows in the
electrode layer 10, the magnetization direction of the magnetic
layers 20 adjacent to the electrode layer 10 may be controlled
through the spin-orbit torque or the spin-transfer torque. The
magnetization direction is determined according to the direction of
the current flowing in the electrode layer 10. FIG. 2A shows that a
current flows perpendicularly to the vertical direction in the case
of spin-orbit torque, and FIG. 2B shows that a spin-polarized
current flows vertically in the case of spin-transfer torque, but
the magnetization direction may vary according to the current or
the spin polarization current, depending on the interface between
material forming the electrode layer 10 and the magnetic layer 20.
Accordingly, when a current is applied to the function
reconfiguring electrode layer 110 of FIG. 1, the magnetization
direction of the function reconfiguring magnetic layer 120 adjacent
to the function reconfiguring electrode layer 110 may be
controlled. The magnetization direction of the function
reconfiguring magnetic layer 120 is determined according to the
direction of the current applied to the function reconfiguring
electrode layer, and the direction of the current is determined
according to the logic operation to be performed by the logic
device.
[0053] In addition, when a current is applied to the input
electrode layer 220, the magnetization direction of the input
magnetic layer 210 adjacent to the input electrode layer 220 may be
controlled. The magnetization direction of the input magnetic layer
210 is determined according to the direction of the current applied
to the input electrode layer 220, and the direction of the current
may be determined according to the input value of the logic
device.
[0054] The above-described spin torque may be used to independently
control the magnetization directions of the function reconfiguring
magnetic layer 120 and the input magnetic layer 210 according to
the present embodiment, which may be parallel or anti-parallel to
each other.
[0055] FIGS. 3A and 3B are diagrams illustrating resistance
according to magnetization directions of the function reconfiguring
magnetic layer 120 and the input magnetic layer 210 of FIG. 1.
[0056] Referring to FIGS. 3A and 3B, the vertical resistance of the
logic function device 1 of FIG. 1 is determined according to a
relative direction of the magnetization direction of the function
reconfiguring unit 100 to the magnetization direction of the input
unit 200. For example, while the magnetization direction of the
function reconfiguring magnetic layer 110 is fixed vertically
downward, the magnetization direction of the input magnetic layer
210 may be changed by applying a potential difference .DELTA.V in
the y direction to the input current layer 220. As shown in FIGS.
3A and 3B, when .DELTA.V is Vo (where Vo>0), the magnetization
direction of the input magnetic layer 210 is vertically upward, so
that the magnetization directions of the function reconfiguring
magnetic layer 110 and the input magnetic layer 210 are
anti-parallel, and when .DELTA.V is -Vo, the magnetization
direction of the input magnetic layer 210 is vertically downward,
so that the magnetization directions of the function reconfiguring
magnetic layer 110 and the input magnetic layer 210 are parallel.
Herein, Vo is equal to or greater than a threshold voltage value
for generating magnetization in the input magnetic layer 210.
[0057] As shown in FIG. 3B, when the magnetization direction of the
function reconfiguring unit 100 and the magnetization direction of
the input unit 200 are parallel to each other, the resistance value
of the logic function device 1 is "R.sub.P", and when they are
anti-parallel, the resistance value is "R.sub.AP". Herein, it is
general that R.sub.AP>R.sub.P is satisfied.
[0058] FIG. 4 is a circuit diagram modeling the logic function
device 1 of FIG. 1.
[0059] Referring to FIG. 4, when a voltage difference is applied
across both ends V and V' of the y direction of the input electrode
layer 220 to apply a current to the input electrode layer 220, the
voltage of an upper end portion of the logic function device 1
becomes an intermediate value of the voltage applied across both
ends V and V' of the input electrode layer 220. The resistance R is
a vertical resistance value according to the magnetization
direction of the function reconfiguring unit 100 and the
magnetization direction of the input unit 200. The resistance
R.sub.A is a horizontal resistance value between the ground voltage
and the output voltage of the function reconfiguring unit 100.
[0060] In the logic function device 1 of FIG. 1, the value V.sub.P
of the output voltage V.sub.out when the magnetization direction of
the function reconfiguring unit 100 and the magnetization direction
of the input unit 200 are parallel is larger than the value Vap of
the output voltage V.sub.out when the magnetization direction of
the function reconfiguring unit 100 and the magnetization of the
input unit 200 are anti-parallel; the output value is set to `1`
when the value of the output voltage V.sub.out is V.sub.P; and the
output value is set to `0` when the value of the output voltage
V.sub.out is Vap, thereby performing a NOT logic operation.
[0061] For example, a current is applied to the function
reconfiguring electrode layer 110, so that the magnetization
direction of the function reconfiguring magnetic layer 120 is set
to the down direction. When the input is "1", the current flows in
the +y direction in the input current layer 220 such that the
magnetization direction of the input magnetic layer 210 is in the
up direction. Accordingly, the magnetization direction (down) of
the function reconfiguring magnetic layer 120 and the magnetization
direction (up) of the input magnetic layer 210 are anti-parallel,
in which the resistance R is referred to as R.sub.AP and the output
voltage V.sub.out is referred to as V.sub.AP. Meanwhile, when the
input is "0", the current flows in the -y direction in the input
current layer 220 so that the magnetization direction of the input
magnetic layer 210 is in the down direction. Accordingly, the
magnetization direction (down) of the function reconfiguring
magnetic layer 120 and the magnetization direction (down) of the
input magnetic layer 210 are anti-parallel, in which the resistance
R is referred to as R.sub.P, and the output voltage V.sub.out is
referred to as V.sub.P. The higher the resistance value of the
resistor R, the higher the voltage drop, and thus the lower the
output voltage V.sub.out, thereby satisfying V.sub.P>V.sub.AP.
When the reference voltage value V.sub.ref is set to satisfy
V.sub.P>V.sub.ref>V.sub.AP; the output value is set to "1"
when the output voltage is higher than the reference voltage value;
and the output value is set to "0" when the output voltage is lower
than the reference voltage value, a NOT logic may be constructed as
in Table 1 blow.
TABLE-US-00001 TABLE 1 Input value Resistance value Output voltage
Output value 1 R.sub.AP V.sub.AP 0 0 R.sub.P V.sub.p 1
[0062] Next, a logic function device with two inputs will be
described.
[0063] FIG. 5 is a cross-sectional view illustrating an x-z plane
of a binary logic function device 2 according to an embodiment of
the present invention, and FIGS. 6A and 6B are cross-sectional
views illustrating a y-z plane of the logic function device 2 of
FIG. 5. FIG. 6A shows a unit 2a and FIG. 6B shows a unit 2b.
[0064] Referring to FIGS. 5 and 6, the logic function device 2
according to an embodiment of the present invention includes an
function reconfiguring unit 100 having magnetization in the
vertical direction set by spin torque caused due to an function
reconfiguring current and an output terminal formed at an end
thereof; and a first input unit 200a and a second input unit 200b
formed on the function reconfiguring unit 100 and having
magnetization in one direction, for example, a vertical direction
set by spin torque caused due to an input current, in which the
output voltage V.sub.out of the output terminal is determined on
the basis of whether the magnetization direction of the function
reconfiguring unit 100 and the magnetization direction of the first
input unit 200a and the magnetization direction of the function
reconfiguring unit 100 and the magnetization direction of the
second input unit 200b are parallel or anti-parallel to each other.
An insulating tunnel junction 300 may be formed between the
function reconfiguring unit 100 and the two input units 200a and
200b.
[0065] The function reconfiguring unit 100 may be configured in the
same manner as in FIG. 1.
[0066] The first input unit 200a includes a first input magnetic
layer 210a formed on the function reconfiguring unit 100 and having
magnetization in one direction, for example, a vertical direction
and the first input magnetic layer 210a, and a first input
electrode layer 220 formed on the first input magnetic layer 210a
and through which current flows to manipulate the magnetization in
the first input magnetic layer 210a. The second input unit 200b
includes a second input magnetic layer 210b formed on the function
reconfiguring unit 100 and having magnetization in the same
direction as the first input unit 200a, for example, in a vertical
direction, and a second input electrode layer 220b formed on the
second input magnetic layer 210b and through which current flows to
manipulate the magnetization of the second input magnetic layer
210b. That is, according to the present embodiment, two input units
200a and 200b are arranged side by side in the x direction on the
function reconfiguring unit 100.
[0067] It may be considered that the logic function device 2 of
FIG. 5 is implemented by connecting two logic function devices 1 of
FIG. 1 to each other in the x direction, and two portions of the
logic function device 2 of FIG. 5 corresponding to the logic
function device 1 of FIG. 1 are referred to as a unit 2a and a unit
2b, respectively.
[0068] FIG. 7 is a circuit diagram modeling the logic function
device 2 of FIG. 5.
[0069] Referring to FIG. 7, a resistance R1 is a vertical
resistance value according to the magnetization direction of the
function reconfiguring unit 100 and the magnetization direction of
the first input unit 200a, and a resistance R2 is a vertical
resistance value according to the magnetization direction of the
function reconfiguring unit 100 and the magnetization direction of
the second input unit 200b. The resistance R.sub.A is a horizontal
resistance value of the function reconfiguring unit 100a of the
unit 2a of FIG. 5, and the resistor RB is a horizontal resistance
value of the function reconfiguring unit 100b of the unit 2b of
FIG. 5.
[0070] Referring to FIG. 7, the output voltage V.sub.out varies
according to the resistance values R1 and R2 constituting the
reconfigurable logic device 2 according to an embodiment of the
present invention.
[0071] Table 2 shows output voltages according to each of the
resistance values R1 and R2 constituting the reconfigurable logic
device according to an embodiment of the present invention.
[0072] Considering that RAP>RP as described in FIGS. 3A and 3B,
V.sub.max>V.sub.1>V.sub.2>V.sub.min is satisfied in the
circuit of FIG. 7.
TABLE-US-00002 TABLE 2 R1 R2 Output voltage (V.sub.out) R.sub.P
R.sub.P V.sub.max R.sub.AP R.sub.P V.sub.1 R.sub.P R.sub.AP V.sub.2
R.sub.AP R.sub.AP V.sub.min
[0073] Based on the characteristics of Table 2, a logic device
corresponding to the following example may be implemented using the
reconfigurable logic device of FIG. 5.
[0074] First, in the logic function device 2 of FIG. 5, the
magnetization direction of the function reconfiguring unit 100 is
in the up direction; the reference voltage Vref is set between the
maximum value V.sub.max of the output voltage V.sub.out and the
first value V.sub.1 of the output voltage V.sub.out; the output
value is set to "1" when the output voltage V.sub.out is greater
than the reference voltage Vref; and the output value is set to "0"
when the output voltage V.sub.out is smaller than the reference
voltage, thereby performing an AND logic operation.
[0075] Specifically, the magnetization direction of the function
reconfiguring magnetic layer 120 is set to the up direction by
applying a current to the function reconfiguring electrode layer
110 of the logic function device 2 of FIG. 5. Herein, when the
input of the first input unit 200a is "1", the magnetization
direction Up of the input magnetic layer 210a constituting the
first input unit 200a and the magnetization direction (Up) of the
function reconfiguring magnetic layer 120 are parallel to each
other, so that the unit 2a of FIG. 5 has a resistance value of
R.sub.P. Meanwhile, when the input of the second input unit 200b is
"0", the magnetization direction (Down) of the input magnetic layer
210b constituting the second input unit 200b and the magnetization
direction (Up) of the function reconfiguring magnetic layer 120 are
anti-parallel to each other, so that the unit 2b of FIG. 5 has a
resistance value of R.sub.AP. When the reference voltage value
V.sub.ref is set to satisfy V.sub.max>V.sub.ref>V.sub.1; the
output value is set to "1" when the output voltage is higher than
the reference voltage value; and the output value is set to "0"
when the output voltage is lower than the reference voltage value,
an AND operation logic device may be configured as shown in [Table
3] through the output voltages of [Table 2]
TABLE-US-00003 TABLE 3 Input value Input value Output of first of
second voltage Output input unit input unit R1 R2 (V.sub.out) value
1 1 R.sub.P R.sub.P V.sub.max 1 0 1 R.sub.AP R.sub.P V.sub.1 0 1 0
R.sub.P R.sub.AP V.sub.2 0 0 0 R.sub.AP R.sub.AP V.sub.min 0
[0076] Next, in the logic function device 2 of FIG. 5, the
magnetization direction of the function reconfiguring unit 100 is
in the up direction; the reference voltage Vref is set between the
second value V.sub.2 of the output voltage V.sub.out and the
minimum value V.sub.min of the output voltage; the output value is
set to "1" when the output voltage V.sub.out is greater than the
reference voltage Vref; and the output value is set to "0" when the
output voltage V.sub.out is less than the reference voltage Vref,
thereby performing an OR logic operation.
[0077] Specifically, the magnetization direction of the function
reconfiguring magnetic layer 120 is set to Up by applying a current
to the function reconfiguring electrode layer 110 of the logic
function device 2 of FIG. 5. Herein, when the input of the first
input unit 200a is "1", the magnetization direction (Up) of the
input magnetic layer 210a and the magnetization direction (Up) of
the function reconfiguring magnetic layer 120 are parallel to each
other, so that the unit 2a of FIG. 5 has a resistance value of
R.sub.P. Meanwhile, when the input of the second input unit 200b is
"0", the magnetization direction (Down) of the input magnetic layer
210b and the magnetization direction (Up) of the function
reconfiguring magnetic layer 120 are anti-parallel to each other,
so that the unit 2b of FIG. 5 has a resistance value of R.sub.AP.
When the reference voltage value V.sub.ref is set to satisfy
V.sub.2>V.sub.ref>V.sub.min, and the output value is set to
"1" when the output voltage is higher than the reference voltage
value, and the output value is set to "0" when the output voltage
is lower than the reference voltage value, a NOR logic operation
may be performed as in [Table 4] through the output voltages of
[Table 2].
TABLE-US-00004 TABLE 4 Input value Input value output of first of
second voltage Output input unit input unit R1 R2 (V.sub.out) value
1 1 R.sub.P R.sub.P V.sub.max 1 0 1 R.sub.AP R.sub.P V.sub.1 1 1 0
R.sub.P R.sub.AP V.sub.2 1 0 0 R.sub.AP R.sub.AP V.sub.min 0
[0078] Next, in the logic function device 2 of FIG. 5, the
magnetization direction of the function reconfiguring unit 100 is
in the down direction; the reference voltage Vref is set between
the maximum value Vmax of the output voltage V.sub.out and the
first value V.sub.1 of the output voltage; the output value is set
to "1" when the output voltage V.sub.out is greater than the
reference voltage Vref; and the output value is set to "0" when the
output voltage V.sub.out is less than the reference voltage Vref,
thereby performing a NOR logic operation.
[0079] Specifically, the magnetization direction of the function
reconfiguring magnetic layer 120 is set to Down by applying a
current to the function reconfiguring electrode layer 110 of the
logic function device 2 of FIG. 5. Herein, when the input of the
first input unit 200a is "1", the magnetization direction (Up) of
the input magnetic layer 210a and the magnetization direction
(Down) of the function reconfiguring magnetic layer 120 are
anti-parallel to each other, so that the unit 2a of FIG. 5 has a
resistance value of R.sub.AP. Meanwhile, when the input of the
second input unit 200b is "0", the magnetization direction (Down)
of the input magnetic layer 210b and the magnetization direction
(Down) of the function reconfiguring magnetic layer 120 are
parallel to each other, so that the unit 2b of FIG. 5 has a
resistance value of R.sub.P. When the reference voltage value
V.sub.ref is set to satisfy V.sub.max>V.sub.ref>V.sub.1, and
the output value is set to "1" when the output voltage is higher
than the reference voltage value, and the output value is set to
"0" when the output voltage is lower than the reference voltage
value, a NOR logic operation may be performed as in [Table 5]
through the output voltage of [Table 2].
TABLE-US-00005 TABLE 5 Input value Input value Output of first of
second voltage Output input unit input unit R1 R2 (V.sub.out) value
1 1 R.sub.AP R.sub.AP V.sub.min 0 0 1 R.sub.P R.sub.AP V.sub.2 0 1
0 R.sub.AP R.sub.P V.sub.1 0 0 0 R.sub.P R.sub.P V.sub.max 1
[0080] Next, in the logic function device 2 of FIG. 5, the
magnetization direction of the function reconfiguring unit 100 is
in the down direction; the reference voltage Vref is set between
the second value V.sub.2 of the output voltage V.sub.out and the
minimum value V.sub.min of the output voltage; the output value is
set to "1" when the output voltage V.sub.out is greater than the
reference voltage Vref; and the output value is set to "0" when the
output voltage V.sub.out is less than the reference voltage Vref,
thereby performing a NAND logic operation.
[0081] Specifically, the magnetization direction of the function
reconfiguring magnetic layer 120 is set to Down by applying a
current to the function reconfiguring electrode layer 110 of the
logic function device 2 of FIG. 5. Herein, when the input of the
first input unit 200a is "1", the magnetization direction Up of the
input magnetic layer 210a and the magnetization direction Down of
the function reconfiguring magnetic layer 120 are anti-parallel to
each other, so that the unit 2a of FIG. 5 has a resistance value of
R.sub.AP. Meanwhile, when the input of the second input unit 200b
is "0", the magnetization direction (Down) of the input magnetic
layer 210b and the magnetization direction (Down) of the function
reconfiguring magnetic layer 120 are parallel to each other, so
that the logic function device 2b of FIG. 6 has a resistance value
of R.sub.P. When the reference voltage value V.sub.ref is set to
satisfy V.sub.2>V.sub.ref>V.sub.min, and the output value is
set to "1" when the output voltage is higher than the reference
voltage value, and the output value is set to "0" when the output
voltage is lower than the reference voltage value, a NOR logic
operation may be performed as in [Table 6] through the output
voltages of [Table 2].
TABLE-US-00006 TABLE 6 Input value Input value Output of first of
second voltage Output input unit input unit R1 R2 (V.sub.out) value
1 1 R.sub.AP R.sub.AP V.sub.min 0 0 1 R.sub.P R.sub.AP V.sub.2 1 1
0 R.sub.AP R.sub.P V.sub.1 1 0 0 R.sub.P R.sub.P V.sub.max 1
[0082] FIG. 8 is a cross-sectional view illustrating a binary logic
function device 3 according to an embodiment of the present
invention.
[0083] Referring to FIG. 8, the logic function device 3 according
to the embodiment of the present invention has multiple function
reconfiguring units 100a and 100b and multiple input units 200a and
200b arranged in horizontal directions respectively, in which the
function reconfiguring units 100a and 100b and the input units 200a
and 200b are formed to vertically correspond to each other, and the
magnetization directions of the multiple function reconfiguring
units 100a and 100b may be set independently of each other.
[0084] According to an embodiment, the multiple function
reconfiguring units 100a and 100b may include an function
reconfiguring electrode layer 110 through which an function
reconfiguring current flows; and multiple function reconfiguring
magnetic layers 120a and 120b horizontally formed on the function
reconfiguring electrode layer 110 at a predetermined interval and
having magnetization in one direction, for example, a vertical
direction, set by an function reconfiguring current. A part of the
function reconfiguring magnetic layers 120a and 120b to which the
voltage is applied in one direction and a remainder of the function
reconfiguring magnetic layers to which no voltage is applied have
magnetic anisotropy different from each other, and the
magnetization directions of the part of the function reconfiguring
magnetic layers and the remainder of the function reconfiguring
magnetic layers may be set opposite to each other by an function
reconfiguring current.
[0085] The logic function device 3 of FIG. 8 is different from the
logic function device 2 of FIG. 5 in that the tunnel junctions 300a
and 300b and the function reconfiguring magnetic layers 220a and
200b below the first and second input units 200a and 200b are
separated from each other.
[0086] It may be considered that the logic function device 3 of
FIG. 8 is implemented by connecting two units 3a and 3b. However,
in the present embodiment, since the function reconfiguring
magnetic layers 120a and 120b are separated from each other, the
magnetization directions of the function reconfiguring magnetic
layers 120a and 120b may be set differently.
[0087] For example, the magnetic anisotropy is instantaneously
lowered by vertically applying a voltage only to one of the units
3a and 3b, thereby reducing the power required to switch the
function reconfiguring magnetic layer of the corresponding logic
function device.
[0088] Specifically, a current is applied to the function
reconfiguring electrode layer 110 of the logic function device 3 of
FIG. 8. Herein, when the above magnetic anisotropy is utilized
through the vertical voltage application, it is possible to apply
the vertical voltage only to the unit 3a. Herein, since the
function reconfiguring magnetic layers 120a and 120b have different
magnetic anisotropy and have switching threshold currents different
from each other, when the current values flowing through the
function reconfiguring electrode layer 110 are taken as a value
between the function reconfiguring magnetic layers 120a and 120b,
only magnetization direction of the function reconfiguring magnetic
layer 120a included in the unit 3a may be selectively switched.
Similarly, when the vertical voltage is applied only to the unit
3b, only the operation setting magnetic layer 120b may be
selectively switched. In this manner, the function reconfiguring
magnetic layers 120a and 120b may be independently controlled
through a current applied to the function reconfiguring electrode
layer 110.
[0089] In this manner, a NOT A AND B operation may be performed
using the logic function device 3 of FIG. 8.
[0090] Specifically, the magnetization direction of the function
reconfiguring magnetic layer 120a included in the unit 3a is set to
the down direction, and the magnetization direction of the function
reconfiguring magnetic layer 120b included in the unit 3b is set to
the up direction. When the input of the first input unit 200a is
"1", the magnetization direction (Up) of the input magnetic layer
210a and the magnetization direction (Down) of the function
reconfiguring magnetic layer 120a are anti-parallel, so that the
logic function device 3a has a resistance value of R.sub.AP. When
the input of the first input unit 200a is "0", the logic function
device (Down) of the input magnetic layer 210a and the
magnetization direction (Down) of the function reconfiguring
magnetic layer 120a are parallel, so that the logic function device
3a has a resistance value of R.sub.P. When the input of the second
input unit 200b is "1", the magnetization direction (Up) of the
input magnetic layer 210b and the magnetization direction (Up) of
the function reconfiguring magnetic layer 120b are parallel, so
that the logic function device 3b has a resistance value of
R.sub.P. When the input of the second input unit 200b is "0", the
magnetization direction (Down) of the input magnetic layer 210b and
the magnetization direction (Up) of the function reconfiguring
magnetic layer 120b are anti-parallel, so that the function
reconfiguring logic device 3b has a resistance value of R.sub.AP.
When the reference voltage value Vref is set to satisfy
V.sub.max>V.sub.ref>V.sub.1; the output value is set to "1"
when the output voltage is higher than the reference voltage value;
and the output value is set to "0" when the output voltage is lower
than the reference voltage value, a NOT A AND B operation may be
performed as shown in [Table 7] through output voltages of [Table
2].
TABLE-US-00007 TABLE 7 Input value Input value Output of first of
second voltage Output input unit input unit R1 R2 (V.sub.out) value
1 1 R.sub.AP R.sub.P V.sub.1 0 0 1 R.sub.P R.sub.P V.sub.max 1 1 0
R.sub.AP R.sub.AP V.sub.min 0 0 0 R.sub.P R.sub.AP V.sub.2 0
[0091] FIG. 9 is a cross-sectional view of a ternary logic function
device 4 according to an embodiment of the invention.
[0092] Referring to FIG. 9, the logic function device 4 includes a
third input unit 200c, a fourth input unit 200d, and a fifth input
unit 200e, and perform a ternary logic operation, in which one
terminal of the function reconfiguring unit 100 located on the
third input unit 200c is connected to the ground voltage, and the
output terminal is horizontally opposite to the one terminal of the
function reconfiguring unit 100 and is located on the fifth input
unit 200e.
[0093] According to an embodiment, the magnetization direction of
the function reconfiguring unit 100 is in the up direction, and the
reference voltage (Vref) is set between the output voltage value
when the magnetization direction of the third input unit 200c and
the magnetization direction of the function reconfiguring unit 100
are parallel, the magnetization direction of the fourth input unit
200d and the magnetization direction of the function reconfiguring
unit 100 are parallel, and the magnetization direction of the fifth
input unit 200e and the magnetization direction of the function
reconfiguring unit 100 are parallel, and the output voltage value
when the magnetization direction of the third input unit 200c and
the magnetization direction of the function reconfiguring unit 100
are anti-parallel, the magnetization direction of the fourth input
unit 200d and the magnetization direction of the function
reconfiguring unit 100 are parallel, and the magnetization
direction of the fifth input unit 200e and the magnetization
direction of the function reconfiguring unit 100 are parallel. The
output value is set to "1" when the output voltage is greater than
the reference voltage, and the output value is set to "0" when the
output voltage is less than the reference voltage, thereby
performing the ternary AND logic operation.
[0094] Specifically, it will be considered that the logic function
device 4 of FIG. 9 may have three units 4a, 4b, and 4c horizontally
connected to each other. The magnetization direction of the
function reconfiguring magnetic layer 120 is set to the up
direction by applying a current to the function reconfiguring
electrode layer 110. Herein, when the input of the third input unit
200c is set to "1", the magnetization direction Up of the input
magnetic layer 210c and the magnetization direction Up of the
function reconfiguring magnetic layer 120 are parallel to each
other, so that the unit 4a has a resistance value of R.sub.P.
Meanwhile, when the input of the fourth input unit 200d is set to
"0", the magnetization direction (Down) of the input magnetic layer
210d and the magnetization direction (Up) of the function
reconfiguring magnetic layer 120 are anti-parallel, so that the
unit 4b has a resistance value of R.sub.AP. In a manner similar to
that shown in Table 2, when the resistances of the units 4a, 4b,
and 4c are all R.sub.P, the output voltage becomes the maximum,
which is called V.sub.max'. The maximum value of the seven output
voltages generated in other cases is called V.sub.1'. According to
definition, V.sub.max'>V.sub.1' is satisfied. When the reference
voltage V.sub.ref is set to satisfy
V.sub.max'>V.sub.ref>V.sub.1', and the output value is set to
"1" when the output voltage is higher than the reference voltage
value, and the output value is set to "0" when the output voltage
is lower than the reference voltage value, a ternary AND operation
may be performed as in [Table 8].
TABLE-US-00008 TABLE 8 Input value Input value Input value of third
of fourth of fifth Output input unit input unit input unit value 1
1 1 1 0 1 1 0 1 0 1 0 0 0 1 0 1 1 0 0 0 1 0 0 1 0 0 0 0 0 0 0
[0095] As mentioned above, the present invention has been described
in detail through the preferred embodiments, but the present
invention is not limited thereto, and various changes and
applications may be made without departing from the technical
spirit of the present invention. Therefore, the true scope of
protection of the present invention should be interpreted by the
following claims, and all technical ideas within the equivalent
scope should be construed as being included in the scope of the
present invention.
* * * * *