Electrical Properties of Dislocations in Plastically
Deformed Float Zone Silicon
J. Simon, E. Yakimov, M. Pasquinelli
To cite this version:
J. Simon, E. Yakimov, M. Pasquinelli. Electrical Properties of Dislocations in Plastically
Deformed Float Zone Silicon. Journal de Physique III, EDP Sciences, 1995, 5 (9), pp.13271336. <10.1051/jp3:1995193>. <jpa-00249382>
HAL Id: jpa-00249382
https://hal.archives-ouvertes.fr/jpa-00249382
Submitted on 1 Jan 1995
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Phys.
J.
III
£Yonce
(1995)
5
SEPTEMBER1995,
1327-1336
1327
PAGE
Classification
Physics
Abstracts
61.70Jc
72.10
Electrical
Properties
Zone Silicon
of
Dislocations
Plastically
in
Deformed
Float
Simon, E. Yakimov(*) and M. Pasquinelli
J-J-
Laboratoire
Photo41ectricite
de
Conducteurs
Marseille
13397
(Received
activity
electrical
The
Abstract.
des
accepted
1994,
December
19
Semi-Conducteurs
des
Oxydes", Facult4
Cedex 20, France
leurs
et
sciences
dislocations
of
created
in
dislocations
dangling
Ininority
recombine
aggregation
due
carriers
Sern~-
les
J4r6me,
Marseille-St-
plastically
(FZ) silicon wafers have been investigated by1neans of Deep
(DLTS), of Light Beam Induced Current (LBIC) Trappings and of
these
dans
"D4fauts
de
1995)
June
22
E.A.882
techniques
et
to
Levels
I-V
generation
the
deformed
Float
Curves.
of
Zone
Spectroscopy
Transient
It
found
was
deep traps
that
associated
to
Dislocations
induce also a soft
breakdown
point defects.
deforIned
diodes
the
in
biased
aluIninium
by1neans
of1nicroplas1nas.
Annealing
of
silicon
reverse
drastically the deep trap density and
the soft
wafers at 1000 °C for I hour
reduces
suppresses
modification
of the point defect
breakdown
in Al-Si diodes, probably due to the
atInosphere and
the
bonds
and
the
of the
reconstruction
of
dislocation
core.
Introduction
1.
Dislocations
known
are
Particulary
in
strongly
to
junctions,
this
devices.
electrical
properties of electronic
of
mechanism
fairly well evaluated by the
recombiin the depletion region and by the
the
influence
influence
be
can
reconibinaison-generation of minority carriers
strength in the quasi-neutral region of the bulk.
nation
possibilities
The
diiserent
mechanism.
in leakage
current
of
theoretical
point
view
[I].
a
observed
The
Thus,
the
has
it
effects
dislocation
morphology and
properties) but also
(extrinsic properties).
the
nature
of FZ
(*)
©
On
Les
of
leave
Editions
the
on
For
contaminants.
wafers
silicon
of
correlated
are
established
been
(which
Institute
de
of
Physique
the
on
the
defects
present in the
dislocations
core
of metallic
impurities and
presence
these
is
it
to control
reasons,
necessary
These
minimize
conditions
two
the
Microelectronics
1995
influence
of
are
of
Academy
related
centers
activity of
electrical
satisfied
also
could
previously been
have
recombination
with
that
defects
These
to
not
of the
on
the
by the
the
dislocations.
the
oxygen
dislocation
use
plastic
Sciences
Chemogolovka
on
(intrinsic
concentration
structure
and
deformation
oxygen).
of
from
only depends
dislocations
of
involved
be
discussed
Russia
JOURNAL
1328
PHYSIQUE
DE
III
N°9
deformation, it is well known that, due
properties can strongly depend on the
[2-S]. Such
temperature of deformation (Td) and also on thermal
treatments
treatments
can
change the dislocation charge or the dislocation
recombination
strength in different ways, e.g
increase of the
charge and therefore
reduces the
decrease
the
dislocation
temperature
an
can
electrical
these defects is, 6], enhancing their
barrier
around
recombination
strength [3].
Kimmerling and Patel [7], like Kveder et at. [8] already reported that the
of
concentrations
by
(DLTS)
hole
analyzed
Deep
Level
Transient
Spectroscopy
reduced
niarkedly
most
traps
were
after the annealing of a deformed
modified
crystal while the density of dislocations
not
was
significantly. Ono and Sumino [9] proposed that plastic deformation
involves
several
kinds of
hole traps in p-type silicon, denoted by DH(0.24), DH(0.33) and DH(0.56). DH(0.33) was attributed by these
related to agglomerations
authors to jogs and kinks, while the other two were
of point defect resulting from
debris.
dislocation
Kveder et at. [8] have
obtained
three peaks,
located at 0.25 eV, 0.39 eV and 0.67 eV above the valence band and they
attributed
the first
level to point defects in the vicinity of dislocations, and the others to dangling bonds.
The aim of the present
work is to investigate the
electrical
created
activity of dislocations
silicon
wafers
deformation
in
by
plastic
FZ
The
in
samples.
investigations
inoxygen
poor
volve the
characterization
of the majority
carrier
evaluation
of the
trap levels by DLTS, the
recombination
strength of the defects by means of Light Beam Induced
Current (LBIC) maps,
and by the analysis of current-voltage (I-V) Curves of metal
Plastically
semiconductor
diodes.
deformed saniples are studied in
dislocation
free regions and in regions containing these defects
before and after subsequent annealings.
the
dislocations
It is found
that
noticeable
have a
recombination
strength which can be
ascribed to the deep levels found in reference [8], that the soft
breakdown of
aluminiuni-silicon
diodes depends on this strength, and that a subsequent annealing at 1000 °C reduces drastically
addition,
In
when
dislocations
dislocation-point
to
of these
the
influence
2.
Experimental
formed
are
interaction,
defect
samples were
from
cut-out
They were optically polished
etching solution (HF; HN031 HCH3C02
wafers.
Dislocation
dislocations.
this
In
a/2
to
sources
axis
and
on
with
one
and
order
in
cm~~)
polished
chemically
=
3
x
10~~
prevent
to
under
[10],
two
a
period of
glide systems
of
dislocations
segments
were
Most
the surface (Fig. 1), their emerging
distributed
the surface.
Figure
across
for
stress
at
have
60°
hour
at
C-PA
of
undesired
a
direction
in
of the
Td
silicon
the
with
by scratching the samples
developed by cantilever bending
were
(ill)
FZ
nucleation
the
introduced
reference
a/2 [101](ill).
face
1:8:3)
were
heating
and
boron-doped (Na
half-loops
dislocation
accordance
in
case,
[110](ill)
electrical
defects.
Rectangular
parallel to [110] then
along the tranversal
atmosphere.
argon
by plastic
their
=
samples
700
°C
in
predominant, namely
Burgers vector parallel
orientation
and
honiogeneously
were
their
schematically the disposition of the dislocaNotice
that a dense
tions.
of
dislocations,
parallel
surface of the sample is also
to the
array
formed, and is equivalent to a subgrain boundary. The dislocation density varied in the range
S x 10~ cm~~ to106 cm~~ [10].
Metal
semiconductor
barriers (11= 1.S mm) were
formed by thermal
evaporation of 300 nm
thick
aluminium layer on
dislocation
free and
dislocation
containing regions. In the latter case,
the emerging segments of dislocations
The metal
barriers.
the depletion region of the
cross
semiconductor
realize
removal
a
p
structure
n
of the
junction,
nietallic
was
choosen
in
describes
order
to
avoid
additional
an
heat
treatment
needed
to
apply subsequent annealings to the samples after the
layer. Indeed, annealings at 1000 C for 1 hour in an argon flow were
and in
order
to
°
ELECTRICAL
N°9
PROPERTIES
ax~
IN
SILICON
1329
dwferent
Diodea u#th
fllaiocaflon
bending
DISLOCATIONS
OF
densiw
pll]
~
iccpa
."
[011]
scmtch
'~
60°
6o
array
~
d'l12 [l10]
Fig.
loops developed
Dislocation
1.
carried
out
Deep
samples.
Spectroscopy
deformed
on
Transient
Level
nique (P.A.R 410, Imax
the
following
duration
=
1
mA) [11].
been
have
parameters
and
Iris
diamond
from
lock-in
compare
choosen:
frequency
bias
by
scratches
measurements
To
with
a
-S
lock-in
with
obtained
spectra
voltage
bending.
cantilever
made
were
the
°
amplifier techsamples,
different
V, filling pulse
S V
with
pulse
21 Hz.
Current (LBIC) mappings were done with a
monochromatic
light spot
Light Beam Induced
(less than 10 pm in diameter) from a
monochromator
and the focusing system of a metallographic microscope while au x
The diffusion lengths (Ln) were
y stage moved the sample.
calculated
front the spectral variation of the local quantum efficiency in the near
infrared
range
correlated
with that of the optical absorption coefficient.
Details of these techniques have been
already published [12].
I-V
Curves
obtained using the Keithley 237 Source
Measurement
Unit when the diodes
were
were
biased.
reverse
Finally,
selective
dislocation
the
density Nd;s
measured
was
by counting the
etch
pits after
photocurrent
response
in the
dislocation
etching (Sirtl etch).
chemical
Results
3.
As-RECEIVED
3.1.
and
the
control
material
characteristic
applied
MATERIAL.
diffusion
initial
is
confirmed
of these
voltage
and
length
no
mappings show
LBIC
was
Ln
by DLTS
dislocation
free
soft-breakdown
=
150
pm.
spectra in
diodes
is
shows
observed
The
wich
no
that
for
of
variation
no
absence
signal
the
voltages
recombination
of
is
reverse
below
detected.
current
10 V.
centers
The
is
reverse
I-V
independent of
JOURNAL
1330
PHYSIQUE
DE
?.
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'"'
j
?
/
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so
'~'
'i""
".
~
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'~'
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=$
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III
'~
"'
7,.
R
~"
'ii
r'
-(
'~fi
~j~ho
~~
1
.39
jj
~~n-
~~t
Fig.
2.
L-B-I-C
photocurrent
Fig.
3.
Optical
rr~icrophotography
3.2.
given
mapp
of
are
formed
in
Figure
and
After
illustrates
2
etch-pit
are
at
Td
distribution
by LBIC
of
Figure
to
period
a
technique.
°C for
700
"
characterized
first
spatial
the
corresponding
distribution
deformation
samples
the
saInple (arbitrary units).
deformed
a
of the
MATERIAL.
DISLOCATED
dislocations
map
~"~"
'l~?1
defects
the
2.
of1
hour,
The
LBIC
by plastic
induced
their
recombination
strength. As shown in Figure 3, the distribution of etch
by Sirtl etch (confirmed by X-ray topography), corresponds to the
attenuation
of the photocurrent in the mapp of Figure 2. Thus, as expected [13], the
dislocations
decrease
the
photocurrent and hence the diffusion length (Ln). The value of Ln is found to decrease
deformation
and
pits
revealed
with
the
length
diffusion
sample
that,
are
Figure
Ln
were
deformation,
the
20
=
used
the
when
pm,
illustrates
4
scratches
several
after
to
up
this
to
Nd;s
106 cm~~.
#
dependency.
increase
photocurrent
the
This
dislocation
response
was
minority
The
mapp
was
density.
unchanged
carrier
obtained
on
a
dislocation
in
regions.
The
We
of
mapp
which
in
Notice
free
density,
dislocation
DLTS
verified
spectra
that
distinguished
agreement
with
the
in
those
carried
DLTS
the
out
signal
deformed
observed
in
on
dislocated
increases
with
regions
the
are
shown
dislocations
samples before annealing and
works [7-9].
previous
in
Figure
density.
their
S
Three
and
Figure
broads
characteristics
6.
peaks
are
in
N°9
ELECTRICAL
PROPERTIES
~WnS
DISLOCATIONS
OF
IN
SILICON
1331
~,~
70~fll
~
56gm
loo
Fig.
This
length
Diffusion
4.
saInple,
FZ
oriented
0
x
map
<
111
computed
contains
>,
thanks
to
several
several
L-B.I.C
scannings
at
pm
wavelengths.
different
scratches.
2
~~~
~
~
lbj
ici
q
I
(d)
ii
OH (0.54)
(0.20)
OH
OH
l10
100
(0.38)
200
250
300
Temperature(K)
Fig.
pulse
D-L-T-S
5.
c) Nd>s
duration
=
6
x
1
ms
spectra
and
10~ cm~~
of
deformed
frequency
lock-in
d) Nd;s
=
9
X
(bias voltage -5 V, filling pulse 5 V with
silicon
10~ cIn~~
Hz). a) Nd,s
b) Nd;s
5 X10~ cm~~
p-type
21
10~ cm~~
"
"
JOURNAL
1332
PHYSIQUE
DE
N°9
III
o
/
(700°C160mn)
Def
DH(0.38)
+
DH(0.54)
ii 000°C160mn
Anneal
Gi
j
a
,~i
/
*
34)
D
~
~~~~'~~~
~~~~"~~~
Deformation
700°C160
DHjo,38j
mn
i
150
loo
200
250
Fig.
D-L-T-S
6.
(bias voltage
Table I.
spectra of
deformed
V, filling pulse
-5
D-L- T-S
DH
Et
pylse
before
duration
1
and
annealing at 1000 °C for
frequency 21 Hz).
after
°
(0.20)
Et
"
Et
0.34 eV
"
(Et
levels
hour
detected
argon.
DH (0.38)
(0.34)
DH
1
lock-in
and
ms
of holes traps (Nt) and energy
ajter annealing at 1000 C for1 hour in
and
0.20 eV
"
silicon
p-type
with
Concentration
results.
deformed samples before
in
5 V
300
K)
Temperature
DH
Et
0.38 eV
(0.54)
0.54 eV
"
Deformafion
700 °C/60 mn
Deformafion
700 °C/60
mn
~
+
t
~ ~
~
~j2 ~~-3
2 xi o12
~
cm'~
N,=
3 xl 0~~
cm'~
Anneal
The
hole
traps Nt is
The
free
evaluated
have
can
soft-breakdown
of
breakdown
is
treatment
is
heat
a
these
to
I-V
peaks
broad
labeled
are
DH(0.20), DH(0.38)
The
energy levels given in eV in the parentheses.
from the magnitude of each peak of the spectrum
Curves
I-V
A soft
region
breakdown
their
with
reverse
Figure 7.
Althought
related
traps
respectively,
Curves
be
attributed
the
current
Schottky
barriers
observed
which
needed
for the
similar
to
to
the
intensity
fornied
does
obtained
those
dislocations
is
found
appear
deformation,
to
and
be
the
in
not
in
dependent
the
diodes
dislocation
made
the
on
thernial
the
free
treatment.
dislocation
I.
in
diodes.
dislocation
in the
samples.
received
as
to
of these
and listed in Table
crystal are presented
dislocated
on
not
DH(0.54),
and
concentration
Thus,
the
In
the
density.
ELECTRICAL
N°9
PROPERTIES
OF
DISLOCATIONS
SILICON
IN
1333
1.00E-02
(d)
°
~
~
~o(C)
C
~
a
~
°
@
~i~
°
a
o
a
o
o
a
~
o
°
o,
@'
fi
a
a
~
e
$
,
~
io
Voltage
(
Fig.
Reverses
7.
I-V
b) Nd;s
3.3.
DISLOCATED
annealed
After
to
of
Table I displays
trap levels
carrier
related
to
of
presence
in our
DH(0.20)
fourth
a
moderately
probably due to a
dislocation
The
are
the
free
reverse
given
in
X
formed
d)
Nd>s
ANNEALING
°C for
a
free
samples
atmosphere.
the density or
Dislocated
°C.
hour
in
argon
an
detected
were
Dislocation
10~ cm~~
X
1000
AT
changes
9
=
period of1
crystal. a)
dislocated
on
either
in
were
the
etch
after
[7, 8], all the peaks
studies
decrease.
1000
obtained
spectra
=
barriers
10~ cm~~
appreciable
pits.
no
dislocation
DLTS
majority
Nt
any
6
AFTER
at
stress
treatment,
this
previous
c) Nd;s
MATERIAL
without
distribution
The
"
Schottky
of
Curves
10~ cm~~
diode.
the
is
could
annealing
which
be
divided
calculated.
peak, with any
activation
dislocated
crystal (Nd;s
during such
contamination
#
shown
In
energy
8
x
for
three
about
o.34
10~ cm~~) after
annealing
In agreement with
specimen are found
peaks. The
of
concentration
DH(0.38) and DH(0.54) while
fact, this peak
of
6.
deformed
of
different
the
by
Figure
in
characteristic
of Nt for
evolution
approxiniately
not
also
are
are
because
is
detected
not
eV, and
which
annealing
this
level
loco
at
is
due
also
to
the
revealed
is
°C.
It is
detected
in
diodes.
I-V
Figure
soft-breakdown
Curves
8.
has
obtained
on
the
annealing,
disappeared. As
After
same
a
dislocated
decrease
shown
in
sample before
of the
Figure 9,
reverse
the
current
current
and
is
after
annealing
observed
measured
iouaNALDEPaYsiwEm-T.s,w9,swwwm199s
in
while
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»
JOURNAL
1334
DE
PHYSIQUE
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N°9
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ELECTRICAL
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1335
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Fig.
I-V
Reverses
9.
cation
b)
diode.
free
dislocations
modified
is
Schottky
containing
Curves
of
Dislocation
and
it is
not
(Nd;s
preclude
8
annealing
after
barriers
diode
7
lo
9
V
9
=
X
10~
that
a
the
defornied
at
°C for I
1000
hour.
a)
Dislo-
cm~~).
dangling
of
reconstruction
bonds
can
occur.
The
soft
about
at
lo
breakdown
V,
be
can
the
as
from
In
conclusion,
wafers
have
bination
a
inducing
junction,
When
and
could
able
are
soft
a
deformed
the
decreases
shown
the
atmosphere
soft
and
to
the
of the
of the
dislocation
of
dislocation
cores
work
was
supported by
charge tube.
space
orland by
a
relaxation
activity of the point
electrical
defect
This
of
could
impurities
aggregation.
by plastic deformation in FZ silicon
generation of different types of recomaggregation.
be
ascribed
bonds
and point defects
to dangling
develop microplasmas when they cross the depletion region of a
created
dislocations
in
the
annealed
are
the
to
at
disappears,
reconstruction
Curves.
I-V
reverse
1000
°C
probably
of the
CNRS-ECOTECH
for I hour,
due to a
dislocation
Acknowledgments
This
voltages of
microplasmas
certainty due to the formation
breakdown
current
space charge region, as the
breakdown
dissapears after the annealing at 1000 °C
activity, due
breakdown
to
reverse
the
decrease
that
breakdown
wafers
in
This
the
samples for
of
modification
electrical
which
centers,
dislocations
These
defects
have
we
noticeable
7 in
of
mesure
lines
density.
inducing
dislocation
the
large
a
dislocation
defect
Figure
in
of the
consequence
the
reconstruction
a
explained by
be
with
of
emergences
with the
increases
(Fig. 8),
observed
France
core.
the
density of trap
modification
of
the
levels
point
JOURNAL
1336
PHYSIQUE
DE
III
N°9
References
iii
El
[2]
Olnling P.,
Ghitani
Pasquinelli M.,
and
H.
E-R-,
Weber
J.
Phys.
L.,
Montelius
III
France
Alexander
(1993)
3
H.
1931-1939.
J.,
Michel
and
Phys.
Rev.
B
32
(1985)
6571-6581.
[3]
Bondarenko
I-E-
E-B-,
and
Yakilnov
Yarikin
N-A-
Yakilnov
[5]
Eremenko
V-G-,
Nikitenko
V-I-
and
Yakimov
[6]
Erelnenko
V-G-,
Nikitenko
V-I-
and
Yakilnov
Kimlnerling
[8]
Kveder
[9]
Ono
[10]
[11]
and
Patel
Pichaud
and
Sulnino
B.,
Minari
G.L., Lang
[12]
Stelnmer
[13]
Mariani
F.
Schroter
of
Martinuzzi
and
D-V-
Thesis
E-B-, Sov. Phys.
JETP
48
E-B-, Sov. Phys.
JETP
42
W.
and
and
Sci.
S.,
J.
Phys.
Kilnmerling L-C-,
63
doctorate
34
122
Ann.
Sol.
(1979)
121-128.
(1984)
(1978)
(1976)
443-450.
598-603.
503-507.
73.
G., Phys.
Zoth
K., J. Appl. Phys. 57 (1985)
M., Appl. Surf.
J.L.,
Nikitenko
J-R-, Appl. Phys. Lett.
V.V., Ossypian Yu.A.,
H.
Miller
L.C.
84
Sol.
V-I-, Phys. Stat.
[4]
[7]
and
(A )
(1990)
(A )
E-B-, Phys. Stat.
Sol.
Stat.
(A )
72
(1982)
287-292.
IV
France
Rev.
G61
Mater.
(1993) 213-217.
(Universit4 de Marseille, 1990).
(1991).
(1977)
Sci.
377-382.
701-704.