20
Toggle and Torque: MRAM at Everspin Technologies Nick Rizzo F.B. Mancoff, R. Whig, K. Smith, K. Nagel, T. Andre, P.G. Mather, S. Aggarwal, J. M. Slaughter, D. Mitchell, S. Tehrani
Toggle
an
d T
orq
ue:
MR
AM
at
Ever
spin
Tec
hn
olo
gie
s
Nic
k R
izzo
F.B
. M
anco
ff, R
. W
hig
, K
. S
mit
h, K
. N
agel
, T
. A
ndre
, P
.G.
Mat
her
, S
. A
ggar
wal
, J.
M. S
laughte
r, D
. M
itch
ell,
S. T
ehra
ni
Eve
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go
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rSp
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ies,
In
c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
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e p
rop
ert
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ctiv
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ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
T
he
lea
din
g d
evel
op
er a
nd
ma
nu
fact
ure
r o
f in
tegra
ted
m
ag
net
ic p
rod
uct
s.
In
du
stry
-fir
st M
RA
M m
anu
fact
ure
r si
nce
Ju
ne
200
6
E
mb
edd
ed M
RA
M s
yst
ems:
1st
SO
C i
nto
pro
du
ctio
n i
n 2
010
In
teg
rate
d m
agn
etic
sen
sors
: 1
stin
teg
rate
d s
yst
em i
n 2
01
0
F
orm
ed a
s E
ver
spin
in J
un
e 2
008
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rev
iou
sly
pa
rt o
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rees
cale
Sem
ico
nd
uct
or
E
xp
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ded
po
rtfo
lio
to
50
pro
du
cts
curr
entl
y
F
ocu
s o
n i
nno
vat
ion
, q
ual
ity
, co
st,
reli
abil
ity
, m
anu
fact
ura
bil
ity
Ev
ersp
inin
tro
du
ctio
n
Eve
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ies,
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c. A
ll
oth
er
pro
du
ct o
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©E
ve
rSp
inT
ech
no
log
ies
20
09
.
Cu
rren
t M
RA
M p
ort
foli
o
48-B
GA
•x8
Asynchro
nou
s p
ara
llel I/O
•x16
Asynchro
no
us p
ara
llel I/O
44-T
SO
PII
•x8
Asynchro
nou
s p
ara
llel I/O
•x16
Asynchro
no
us p
ara
llel I/O
8-D
FN
–S
PI-
com
patible
serial I/O
–40 M
Hz; N
o w
rite
dela
y
16-b
it I/O
Part
Num
ber
Density
Configura
tion
MR
4A
16
B16
Mb
1M
X1
6
MR
2A
16
A4
Mb
25
6K
x1
6
MR
1A
16
A2
Mb
12
8K
x1
6
MR
0A
16
A1
Mb
64
Kx16
8-b
it I/O
Part
Num
ber
Density
Configura
tion
MR
2A
08
A4
Mb
51
2K
x8
MR
0A
08
B1
Mb
12
8K
x8
MR
256A
08
B25
6K
b32
kX
8
SP
I I/O
Part
Num
ber
Density
Configura
tion
MR
25H
10
1M
b12
8K
x8
MR
25H
512
51
2K
b64
Kx8
MR
25H
256
25
6K
b32
Kx8
16-b
it I/O
Part
Num
ber
Density
Configura
tion
MR
4A
16
B16
Mb
1M
X1
6
MR
2A
16
A4
Mb
25
6K
x1
6
MR
1A
16
A2
Mb
12
8K
x1
6
MR
0A
16
A1
Mb
64
Kx16
8-b
it I/O
Part
Num
ber
Density
Configura
tion
MR
2A
08
A4
Mb
51
2K
x8
MR
0A
08
B1
Mb
12
8K
x8
MR
256A
08
B25
6K
b32
kX
8
SP
I I/O
Part
Num
ber
Density
Configura
tion
MR
25H
10
1M
b12
8K
x8
MR
25H
512
51
2K
b64
Kx8
MR
25H
256
25
6K
b32
Kx8
Eve
rSp
in™
an
d t
he
Eve
rSp
inlo
go
are
tra
de
ma
rks
of
Eve
rSp
inT
ech
no
log
ies,
In
c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
es
are
th
e p
rop
ert
y o
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eir
re
spe
ctiv
e o
wn
ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
•2009:
Red
Her
ring A
war
d:
Top 1
00 m
ost
pro
mis
ing
tec
h c
om
pan
ies
•2008:
Busi
nes
s W
eek “
Most
Succ
essf
ul
Sta
rtups”
•2008:
Forb
es/W
olf
e E
mer
gin
g T
ech R
eport
s –
“com
pan
ies
to w
atch
”
•2007:
Des
ign N
ews
Gold
en M
ouse
trap
Aw
ard
•2007:
R&
D M
agaz
ine
-T
op 1
00 I
nven
tions
of
2007
•2007:
EE
Tim
es C
hin
a A
ce A
war
d -
Bes
t P
roduct
of
the
Yea
r –
Mem
ory
•2007:
Japan
Em
bed
ded
Syst
ems
Expo -
Mem
ory
of
Yea
r
•2007:
In-S
tat’
s In
novat
ion A
war
d
•2006:
Nam
ed P
roduct
of
the
Yea
r by E
lect
ronic
Pro
duct
s
•2004:
MIT
Tec
hnolo
gy R
evie
w-
MR
AM
“T
oggle
”is
one
of
5 K
ille
r 2003 P
aten
ts
Ev
ersp
inM
RA
M R
eco
gn
ized
as
Ind
ust
ry
Bre
ak
thro
ug
h P
rod
uct
Most
Su
ccess
ful
US
Sta
rtu
ps
Eve
rSp
in™
an
d t
he
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rSp
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go
are
tra
de
ma
rks
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rSp
inT
ech
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ies,
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c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
es
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e p
rop
ert
y o
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ctiv
e o
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ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
Ev
ersp
inA
pp
lica
tio
ns,
Cu
sto
mer
s
Valu
e d
iffe
ren
tiati
on
No
n-v
ola
tile
Fa
st r
ead
an
d w
rite
Un
lim
ited
en
du
ran
ce
Hig
hly
rel
iab
le
Log
os,
tra
dem
ark
s, i
mag
es a
nd
cop
yri
gh
t re
fere
nce
s ar
e th
e p
rop
erty
of
the
resp
ecti
ve
com
pan
ies
note
d.
Eve
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in™
an
d t
he
Eve
rSp
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go
are
tra
de
ma
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rSp
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ech
no
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ies,
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c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
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es
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e p
rop
ert
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ctiv
e o
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ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
Mem
ory
Co
mp
ari
son
To
ggle
MR
AM
(18
0 n
m)
To
ggle
MR
AM
(65
nm
)*
ST
MR
AM
(65
nm
)*
FL
AS
H
(65
nm
)+
DR
AM
(65
nm
)+
SR
AM
(65
nm
)+
cell
siz
e (µ µµµ
m2)
1.2
50
.16
0.0
4†
0.0
40
.03
0.3
Rea
d t
ime
35
ns
10
ns
10
ns
10
-50
ns
10
ns
1 n
s
Pro
gra
m t
ime
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s5
ns
10
ns
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-100
ms
10
ns
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s
Pro
gra
m
ener
gy
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pJ
100
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Nee
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esh
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du
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015
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015
rea
d,
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te>
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15
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015
No
n-v
ola
tili
tyY
ES
YE
SY
ES
YE
SN
ON
O
* 6
5n
m M
RA
M v
alu
es a
re
pro
jecte
d
+ T
hes
e valu
es a
re
fro
m t
he
ITR
S r
oad
map
†T
his
cel
l si
ze
on
ly c
on
sid
ers
bit
are
a a
nd
ign
ores
CM
OS
lim
itati
on
s
Toggle
MR
AM
Eve
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ies,
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ll
oth
er
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du
ct o
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rop
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ve
rSp
inT
ech
no
log
ies
20
09
.•Sen
se p
ath e
lect
rica
lly i
sola
ted
fro
m p
rogra
m p
ath
ON
for
sensi
ng,
OF
F f
or
pro
gra
mm
ing
I RefI s
ense
Wri
te L
ine
1
Wri
te L
ine
2I
I
Bo
tto
m
Ele
ctro
de
To
p
Ele
ctro
de
Mag
net
ic T
unnel
Junct
ion
To
gg
le M
RA
M B
it C
ell
H
H
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rSp
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ech
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ies,
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c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
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rop
ert
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ctiv
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ers
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©E
ve
rSp
inT
ech
no
log
ies
20
09
.
To
gg
le s
wit
chin
g f
or
ba
lan
ced
SA
F
H>Hsw
M1
M2
AF
coupli
ng
M1
= M
2
H>Hsat
H<Hsw
•Low
er E
ner
gy t
o “
flop”
and s
ciss
or
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ld e
xce
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SA
F s
tren
gth
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ies,
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ll
oth
er
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du
ct o
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rop
ert
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ctiv
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.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
Wri
te
Lin
e 2
Wri
te
Lin
e 1
Wri
te L
ine
1
Wri
te L
ine
2
t 0t 1
t 2t 3
t 4
H
To
gg
le M
RA
M S
wit
chin
g S
eq
uen
ce
I
00
IH
I
H
I
•Ph
ased
curr
ent
pu
lses
pro
du
ce r
ota
ting
fie
ld
•To
gg
le –
sam
e fi
eld
seq
uen
ce a
lway
s ch
ang
es s
tate
of
bit
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ies,
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ll
oth
er
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du
ct o
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rop
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©E
ve
rSp
inT
ech
no
log
ies
20
09
.
0
80
160
240
320
400
480
560
060
120
180
240
300
360
420
480
540
600
H<
Hsw
: D
oes
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Sw
itch
Hsw
<H
<H
sat:
Sw
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es
H>
Hsa
t: D
oes
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sw
itch
H1 (
Oe)
H2 (Oe)
To
gg
le b
it s
wit
chin
g
•Thre
shold
pro
gra
mm
ing e
nsu
res
hig
h r
elia
bil
ity
Th
eore
tica
l si
mu
lati
on
of
Toggle
sw
itch
ing
Op
era
ting
Reg
ion
T =
125 º
C
Non-S
witch
ing
Regio
n
Bit L
ine
Curr
en
t
Digit Line Current
Op
era
ting
Reg
ion
T =
125 º
C
Non-S
witch
ing
Regio
n
Bit L
ine
Curr
en
t
Digit Line Current4M
hig
h s
pee
d m
emory
tes
t
0 e
rrors
Sp
in T
orq
ue
MR
AM
Eve
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rSp
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ies,
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ll
oth
er
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du
ct o
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rop
ert
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ctiv
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.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
Mv
iaL
ow
er
Ele
ctro
de
Dig
it L
ine
Bit
lin
e
I
Toggle
MR
AM
Cell
siz
e ≈
1 µ
m2
CM
OS
0.1
8µ
m
I
Com
pari
son
of
0.1
8 µ µµµ
m T
oggle
MR
AM
an
d 6
5n
m S
T-M
RA
M
To
gg
le
bit
ST
bit
ST
-MR
AM
Cel
l si
ze ≈
0.0
4 µ
m2
CM
OS
65n
m
I ≈
100 µ µµµ
A
Toggle
MR
AM
:
•lik
ely
more
rel
iable
•in p
roduct
ion
ST
-MR
AM
has potential to be:
•hig
her
den
sity
–(i
f J c
can b
e
reduce
d t
o u
tili
ze m
inim
um
pas
s
XT
OR
)
•low
er w
rite
pow
er
Bit
lin
e
Mvia
Dig
it
Lin
e
Mag
net
ic
Cla
ddin
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Top V
iew
Sid
e V
iew
Rea
d X
tor
Eve
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ies,
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ll
oth
er
pro
du
ct o
r se
rvic
e n
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rop
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©E
ve
rSp
inT
ech
no
log
ies
20
09
.
-0.8
-0.4
0.0
0.4
0.8
1.2
50
0
55
0
60
0
65
0
70
0
75
0
80
0
85
0
90
0
010
20
30
40
50
60
70
Resistance (ohms)
DC
curr
ent
(mA
)
MR (%)
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-0.4
0.0
0.4
0.8
1.2
50
0
55
0
60
0
65
0
70
0
75
0
80
0
85
0
90
0
010
20
30
40
50
60
70
Resistance (ohms)
DC
curr
ent
(mA
)
MR (%)
•Use
sp
in m
om
entu
m f
rom
curr
ent
to c
han
ge
dir
ecti
on o
f S
, m
.
m∆
SN
et c
han
ge
inh
=S
per
e−
Fix
ed
Lay
er
Tu
nn
el
Bar
rier
Fre
e
layer
Torque
tS=
∆∆
Rem
anen
tlo
op
: 1
00
ms I-
pu
lse
TMR (%)
0.1
2 µ
m x
0.1
9 µ
m
CF
B F
ree
layer
on
Mg
O
100
nm
Jc
~ 1
06-1
07
A/c
m2
Sp
in T
orq
ue
Pro
gra
mm
ing f
or
Hig
h D
ensi
ty,
Lo
w P
ow
er M
RA
M
•Opti
cal
pat
tern
ing o
f
0.1
um
bit
s
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rSp
in™
an
d t
he
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rSp
inlo
go
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tra
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ma
rks
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rSp
inT
ech
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ies,
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c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
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es
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rop
ert
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ctiv
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.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
•Lo
wer
th
e R
A u
nti
l m
inim
um
Ch
all
enge
of
ST
-MR
AM
:
Red
uce
cri
tica
l cu
rren
t d
ensi
ty Jc
I Pas
s
tran
sist
or
MT
J
Vsw
∝RAVbd
∝lo
g(RA
)
⇒
00.5
11.5
0
0.2
0.4
0.6
0.81
Vap
pli
ed
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itch
ing
Dis
trib
uti
on
Bre
akdow
n
Dis
trib
uti
on
Vsw
Vbd
Nee
d >
12
σse
par
atio
n
•Isat≈
500
µ µµµA/µ µµµ
m g
ate
wid
th
for
Si
XT
OR
•Low
Jc
⇒sm
all
pas
s X
tor
•Low
Jc
⇒no t
unnel
bar
rier
bre
akdow
n
For h
igh
den
sity
:F
or h
igh
reli
ab
ilit
y:
Eve
rSp
in™
an
d t
he
Eve
rSp
inlo
go
are
tra
de
ma
rks
of
Eve
rSp
inT
ech
no
log
ies,
In
c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
es
are
th
e p
rop
ert
y o
f th
eir
re
spe
ctiv
e o
wn
ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
0.4
0.6
0.81
1.2
1.4
1.6
1.8
1.0
10
.01
00
.010
00
.0
Bre
ak
dow
n v
olt
age
(Vbd)
vs.
RA
com
pari
son
Vbd
(V)
RA
(Ω µ
m2)Oper
atin
g
Ran
ge
for
ST
-MR
AM
•quas
ista
ticVbd
•bit
siz
e ≈
0.1
x0.2
µm
2
•Vbd
dec
reas
es a
ppro
x. lo
gar
ithm
ical
ly a
s R
A d
ecre
ases
.
Eve
rSp
in™
an
d t
he
Eve
rSp
inlo
go
are
tra
de
ma
rks
of
Eve
rSp
inT
ech
no
log
ies,
In
c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
es
are
th
e p
rop
ert
y o
f th
eir
re
spe
ctiv
e o
wn
ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
To
red
uce
Jc
for
spin
to
rqu
e sw
itch
ing
()
()(
)s
ks
cM
Ht
Me
Jπ
εα
21
2+
≈h
I
Sp
in t
orq
ue
Hig
her
eff
icie
ncy
ε
Hig
her
MR
Low
dam
pin
g (
α)
free
lay
er
Per
pen
dic
ula
r Hk
in f
ree
lay
er
Low
Ms
and/o
r
thin
ner
fre
e la
yer
(Eb
∝ ∝∝∝MsV
)
•Nee
d c
om
bin
atio
n o
f good p
roper
ties
for
low
Jc
TkE b
b
e0τ
τ=
Tim
e t
o d
ata
loss
Eve
rSp
in™
an
d t
he
Eve
rSp
inlo
go
are
tra
de
ma
rks
of
Eve
rSp
inT
ech
no
log
ies,
In
c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
es
are
th
e p
rop
ert
y o
f th
eir
re
spe
ctiv
e o
wn
ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
ST
Sw
itch
ing a
nd
bre
ak
do
wn
fro
m
16k
b C
MO
S a
rrays
05
00
10
00
15
00
20
00
0
0.51
V(m
V)
Pro
ba
bil
ity
Bit
s
swit
ch
ed
Break
dow
n
•Pu
lse d
urati
on
tp
= 1
00n
s
•Bit
siz
e:
0.1
µ µµµm
x 0
.18
µ µµµm
Sep
ara
tio
n>
20
σ σσσ
0200
400
600
800
110
3×
0
50
100
150
Frequency
Bit
res
ista
nce
(Ω
)
His
togram
of
several
hu
nd
red
bit
s in
low
R s
tate
sw
itch
ed
1000 t
imes
Bef
ore
puls
es
Aft
er
1000 p
uls
es
(50 n
s dura
tion)
•Good
sep
arati
on
> 1
2σ σσσ
, b
ut
nee
d t
o e
val.
larger
nu
mb
er o
f b
its,
more
cycle
s
•Vo
ltag
e in
clu
des
pa
ss t
ran
sist
or
Eve
rSp
in™
an
d t
he
Eve
rSp
inlo
go
are
tra
de
ma
rks
of
Eve
rSp
inT
ech
no
log
ies,
In
c. A
ll
oth
er
pro
du
ct o
r se
rvic
e n
am
es
are
th
e p
rop
ert
y o
f th
eir
re
spe
ctiv
e o
wn
ers
.
©E
ve
rSp
inT
ech
no
log
ies
20
09
.
T
oggle
MR
AM
in p
roduct
ion (
since
2006)
and i
s a
hig
hly
rel
iable
,
fast
, nonvola
tile
mem
ory
.
S
T-M
RA
M h
as p
ote
nti
al f
or
hig
her
den
sity
, lo
wer
pow
er i
f I sw
can
be
furt
her
red
uce
d.
•Fro
m s
wit
chin
g k
ilobit
CM
OS
arr
ays
at tp
= 1
00ns:
<I sw>
≈0.5
mA
, <Eb/kbT
> ≈
75
<σsw
> ≈
4%
, <
σbd>
≈3%
Sep
arat
ion >
12σ
Su
mm
ary
