Electrical properties of InSb p-n junctions prepared by diffusion methods
InSb p-n junctions were prepared by three diffusion methods, including isothermal, two-temperature and two-stage diffusion processes. The current-voltage characteristics were measured as a function of temperature and bias voltage. The highest values of the resistance-area product at zero bias have b...
Збережено в:
| Опубліковано в: : | Semiconductor Physics Quantum Electronics & Optoelectronics |
|---|---|
| Дата: | 2016 |
| Автори: | , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2016
|
| Онлайн доступ: | https://nasplib.isofts.kiev.ua/handle/123456789/121603 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Electrical properties of InSb p-n junctions prepared by diffusion methods / A.V. Sukach, V.V. Tetyorkin, A.I. Tkachuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2016. — Т. 19, № 3. — С. 295-298. — Бібліогр.: 20 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-121603 |
|---|---|
| record_format |
dspace |
| spelling |
Sukach, A.V. Tetyorkin, V.V. Tkachuk, A.I. 2017-06-14T17:53:19Z 2017-06-14T17:53:19Z 2016 Electrical properties of InSb p-n junctions prepared by diffusion methods / A.V. Sukach, V.V. Tetyorkin, A.I. Tkachuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2016. — Т. 19, № 3. — С. 295-298. — Бібліогр.: 20 назв. — англ. 1560-8034 DOI: 10.15407/spqeo19.03.295 PACS 73.40.Gk, 73.40.Kp https://nasplib.isofts.kiev.ua/handle/123456789/121603 InSb p-n junctions were prepared by three diffusion methods, including isothermal, two-temperature and two-stage diffusion processes. The current-voltage characteristics were measured as a function of temperature and bias voltage. The highest values of the resistance-area product at zero bias have been obtained for the junctions prepared using the two-stage diffusion process. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Electrical properties of InSb p-n junctions prepared by diffusion methods Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Electrical properties of InSb p-n junctions prepared by diffusion methods |
| spellingShingle |
Electrical properties of InSb p-n junctions prepared by diffusion methods Sukach, A.V. Tetyorkin, V.V. Tkachuk, A.I. |
| title_short |
Electrical properties of InSb p-n junctions prepared by diffusion methods |
| title_full |
Electrical properties of InSb p-n junctions prepared by diffusion methods |
| title_fullStr |
Electrical properties of InSb p-n junctions prepared by diffusion methods |
| title_full_unstemmed |
Electrical properties of InSb p-n junctions prepared by diffusion methods |
| title_sort |
electrical properties of insb p-n junctions prepared by diffusion methods |
| author |
Sukach, A.V. Tetyorkin, V.V. Tkachuk, A.I. |
| author_facet |
Sukach, A.V. Tetyorkin, V.V. Tkachuk, A.I. |
| publishDate |
2016 |
| language |
English |
| container_title |
Semiconductor Physics Quantum Electronics & Optoelectronics |
| publisher |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| format |
Article |
| description |
InSb p-n junctions were prepared by three diffusion methods, including isothermal, two-temperature and two-stage diffusion processes. The current-voltage characteristics were measured as a function of temperature and bias voltage. The highest values of the resistance-area product at zero bias have been obtained for the junctions prepared using the two-stage diffusion process.
|
| issn |
1560-8034 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/121603 |
| citation_txt |
Electrical properties of InSb p-n junctions prepared by diffusion methods / A.V. Sukach, V.V. Tetyorkin, A.I. Tkachuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2016. — Т. 19, № 3. — С. 295-298. — Бібліогр.: 20 назв. — англ. |
| work_keys_str_mv |
AT sukachav electricalpropertiesofinsbpnjunctionspreparedbydiffusionmethods AT tetyorkinvv electricalpropertiesofinsbpnjunctionspreparedbydiffusionmethods AT tkachukai electricalpropertiesofinsbpnjunctionspreparedbydiffusionmethods |
| first_indexed |
2025-11-25T21:07:28Z |
| last_indexed |
2025-11-25T21:07:28Z |
| _version_ |
1850550821211602944 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 3. P. 295-298.
doi: 10.15407/spqeo19.03.295
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
295
PACS 73.40.Gk, 73.40.Kp
Electrical properties of InSb p-n junctions prepared
by diffusion methods
A.V. Sukach1, V.V. Tetyorkin1, A.I. Tkachuk2
1V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine,
41, prospect Nauky, 03028 Kyiv, Ukraine
2V. Vinnichenko Kirovograd State Pedagogical University, Kirovograd, Ukraine
Tel. (38 044) 525-1813, e-mail: teterkin@isp.kiev.ua
Abstract. InSb p-n junctions were prepared by three diffusion methods, including
isothermal, two-temperature and two-stage diffusion processes. The current-voltage
characteristics were measured as a function of temperature and bias voltage. The highest
values of the resistance-area product at zero bias have been obtained for the junctions
prepared using the two-stage diffusion process.
Keywords: InSb, photodiode, two-stage diffusion, annealing.
Manuscript received 12.04.16; revised version received 20.07.16; accepted for
publication 13.09.16; published online 04.10.16.
1. Introduction
InSb and HgCdTe photodiodes are basic photodetectors
for effective registration of IR radiation in the spectral
range of 3 to 5 μm [1]. Both photodiodes have
comparable operational characteristics and threshold
parameters at 77 K. Widespread usage of InSb
photodiodes is based on well developed technology of
bulk material, long-term stability and reproducibily of
their parameters. Up to date, 2052×2052 focal matrix is
developed on InSb bulk material [2]. The commonly
used methods for manufacture InSb p-n junctions are
implantation of light ions Be [3-5], Mg [3] and Zn [6], as
well as diffusion of acceptor impurity Cd [7-12]. In
diffusion photodiodes, rather high value of the
differential resistance – area product R0A =
3.4·103 Ω·cm2 was already reported in 1961 [7]. For
comparison, in modern commercial photodiodes this
parameter has typical values of 5·103 Ω·cm2 [13].
Moreover, the specific detectivity in commercial
photodiodes D*
λ = 1·1011 cm·Hz1/2·W–1 is almost five
times less than the theoretically possible value [13]. The
reason for this discrepancy may be excessive currents,
which nature is not fully understood yet. A model for the
trap-assisted tunnelling current flowing through the
depletion region has been developed for interpretation of
experimental data in HgCdTe and InSb photodiodes [1].
This model involves uniform distribution of deep traps
through the depletion region [8, 11]. On the contrary, in
a model of non-homogeneous p-n junction, carrier
tunnelling with participation of extended defects, such as
dislocations, is assumed to be responsible for the excess
current [12, 14]. In this case, local areas exist in the
depletion region, which are characterized by higher
electric field. The dark current can flow through these
areas by means of trap-assisted or interband tunnelling
as well as through the uniform regions by means of
generation-recombination or diffusion mechanism [15].
Obviously, grown-in and process-induced dislocations
can effect on the carrier transport. The process-induced
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 3. P. 295-298.
doi: 10.15407/spqeo19.03.295
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
296
dislocations in InSb photodiodes are related with high
plasticity of bulk material. High concentration of point
and extended defects in freshly prepared junctions
results in a problem of separation of electrical and
metallurgical junctions. In implanted photodiodes, this
problem is resolved by photonic or thermal annealing
[4], whereas in diffusion ones two-temperature diffusion
method is used [9, 12, 14].
Based on the above mentioned, the purpose of this
study is to clarify impact of various diffusion methods
on dark current and threshold parameters of InSb p-n
junctions.
2. Samples and experimental methods
The investigated p-n junctions were produced by
diffusion of cadmium into single crystal substrates of n-
type conductivity with crystallographic orientation (100)
and average thickness close to 500 μm. The
concentration and mobility of electrons in the substrates
were (1…2)·1015 cm–3 and 5.0·105 cm2/V·s at 77 K,
respectively. The average density of dislocations (etch
pits density) was less than 350 cm–2 [16]. The damaged
layer was removed by chemical dynamic polishing using
a polishing etchant 2% Br2+HBr. The surface quality
was controlled by an interference microscope. The
measured roughness at the surface after polishing was
~0.03 µm. To prevent re-evaporation of constituents,
additionial amount of InSb and elemental Sb was placed
into a silica ampoule to ensure the saturation vapor
condition.
Three methods of cadmium diffusion into n-InSb
substrates were implemented: i) isothermal diffusion at
420 °C for 30 min; ii) two-temperature diffusion for
30 min, when Cd source and InSb substrate were in
different temperature zones 380 and 420 °C; iii) two-
stage diffusion, when after isothermal diffusion of Cd at
380 °C the thermal annealing at 420 °C was carried out
for 60 min in a separate ampoule. Hereafter, the p-n
junctions prepared by these methods are labeled as TR1,
TR2 and TR3, respectively.
The p-n junction depth was determined by
measuring the sign of thermo-EMF by using the probe
method during sequential chemical etching the doped
surface layer. The determined values were 3.5±0.5,
3.0±0.5 and 4.5±0.5 µm for TR1, TR2 and TR3
junctions, respectively. The active area of mesa
structures was 1.4·10–2 cm2. As determined by the
differential Hall effect [17], the average concentration of
holes in the doped layer was (7±1)·1018 cm–3 at 77 K.
Ohmic contacts to p- and n-type regions of the junctions
were prepared using In-Zn alloy and pure In,
respectively. Formation of ohmic contacts and
purification of mesas was carried out in a hydrogen
atmosphere at ~350 °C for 5 to 10 min. Thin
polycrystalline films of CdTe were used as passivation
and protective layers due to good agreement between
lattice parameters and thermal expansion coefficients of
CdTe and InSb. By using polycrystalline CdTe, the
density of interface states in the CdTe-InSb
heterojunction can be 3 to 4 times reduced as compared
to that at the oxide-InSb interface [18]. The current-
voltage and high-frequency (1 MHz) capacitance-
voltage characteristics were measured as functions of the
bias voltage and temperature.
3. Results and discussion
The capacitance-voltage characteristics are shown in
Fig. 1. As seen, experimental data are linearized in
coordinates C–3–U, which indicates formation of
linearly-graded p-n junctions. The dopant concentration
gradient a, as well as the diffusion voltage UD and the
depletion layer width at zero bias W0 have been
estimated from the capacitance measurements.
Appropriate data are summarized in Table. Note that the
diffusion voltage equals 180 mV for TR1 junction and
160 mV for TR2 and TR3 junctions.
Typical current-voltage characteristics are shown in
Fig. 2. The following peculiarities should be pointed out.
In TR1 and TR2 junctions, the forward current exhibits
two exponential branches, which can be approximated
by the following expression:
( ) ( )
⎥
⎦
⎤
⎢
⎣
⎡
β
−
+⎥
⎦
⎤
⎢
⎣
⎡ −
=
kT
IRUe
I
E
IRUe
II SS expexp 02
0
01 , (1)
where the characteristic energy E0 equals 29 and 32 meV
for TR1 and TR2 junctions, respectively. Other
parameters are shown in Table. At the same time, in the
TR3 junction only one exponential branch is observed,
which is described by the second term in the equation (1).
-200 -100 0 100 200
0
1
2
3
4
5
6
TR3
TR2
TR1
C
-3
x1
0-2
9 , F
-3
U, mV
Fig. 1. Capacitance-voltage characteristics of InSn p-n
junctions prepared using TR1, TR2, TR3 methods of diffusion.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 3. P. 295-298.
doi: 10.15407/spqeo19.03.295
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
297
0 50 100 150 200
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
TR3
TR2
TR1
I,
A
U, mV
Fig. 2. Forward (open dots) and reverse (close dots) current-
voltage characteristics of InSb p-n junctions.
6 8 10 12 14
10-2
10-1
100
101
102
103
104
105
TR3
TR2
TR1
R
0A
, Ω
c
m
2
103/T, K-1
Fig. 3. Temperature dependences of the differential resistance-
area product.
The temperature dependences of R0A product is
shown in Fig. 3. The differential resistance was obtained
from the forward I–U characteristics at the bias voltage
U = 10 mV. In the temperature range 87–150 K, the
experimental data are well linearized in the coordinates
ln(R0A) – 103/T. At temperatures ≤87 K, deviation from
the linear dependence is observed for TR1 and TR2
junctions, which is caused by the influence of the tunnel
current. The tunnel current is also observed at low forward
biases in these junctions (see Fig. 2, curves 1 and 2). A
distinctive feature of the current-voltage characteristic of
TR3 junction is absence of tunnel current component,
which is also confirmed by a linear dependence of R0A on
the reverse temperature in the whole temperature range
77…150 K. The activation energy for a differential
resistance is estimated to be 180 meV for TR3 junction.
Taking into account the ideality coefficient in this junction
β = 1.6, one can conclude about the contribution of
diffusion and generation-recombination currents to the
total dark current in a roughly equal proportion. Lower
activation energy of 140 meV and higher value of the
ideality coefficient for TR1 and TR2 junctions is
explained by the main contribution of generation-
recombination current to the measured dark current. Note
that the value of the product R0A = 3.5·104 Ω·cm2 at 77 for
TR3 junction almost an order of magnitude higher than
that of commercial photodiodes [13]. It can be explained
by passivation of mezas with cadmium telluride as well as
the higher quality of the junction itself. The detailed
analysis of tunnel currents in diffusion InSb junctions is
given in [12, 14]. An additional evidence of the TR3
junction quality was obtained from the analysis of
generation current at the reverse biases. The effective
lifetime τ0 in the depletion region is almost an order of
magnitude higher in comparison with TR1 and TR2
junctions (see Table).
The reverse current-voltage characteristics are
shown in Fig. 4. The experimental data were
approximated by a power dependence I ~ Um. The
exponent m equals 1.0 and 0.6 in TR1 and TR2 for the
voltage ranges 1…10 and 10…200 mV, respectively.
The appropriate value of 0.4 was obtained for TR3
junction. At the reverse biases ≥1 V, the exponent m
sharply increases to 5 for TR1 and TR2 junctions, and
100 101 102 103 104
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
TR3
TR2
TR1
I,
A
U, mV
Fig. 4. Reverse current-voltage characteristics of InSb p-n
junctions.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 3. P. 295-298.
doi: 10.15407/spqeo19.03.295
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
298
up to 13 for TR3 junction. The breakdown voltage UB
that is measured at the current density 1.0 A/cm2 [19]
was 2.3, 5.4 and 7.5 V for TR1, TR2 and TR3 junctions,
respectively. Experimental values of m and UB for TR1
and TR2 junctions can be explained within a model of
tunneling breakdown in the inhomogeneous p-n junction
[14]. A sharp increase in the current in TR3 junction and
higher values of the breakdown voltage can be explained
by the avalanche breakdown [9]. However, additional
investigations are required for it. It should be pointed out
that in TR3 junction the dark current density at the
reverse bias 0.2 V equals to 3.2·10–6 A/cm2, which is
several orders of magnitude less than the values reported
in literature [3, 6, 7, 14]. However, this value exceeds
almost three times the theoretical one required to
implement BLIP regime in InSb photodiodes [4]. An
additional reason for the large dark currents in TR1 and
TR2 junctions in comparison with TR3 junctions may be
generation of point and extended defects at the
metallurgical junction caused by retrograde solubility of
cadmium in InSb [20].
Table. Parameters of diffusion InSb p-n junctions at Т = 77 K.
M
et
ho
d
of
di
ff
us
io
n
I 0
1,
A
R 0
A,
Ω
·c
m
2
I 0
2,
A
β
a,
c
m
–4
W
0, µm
τ 0
, s
TR1
TR2
TR3
1.3·10–6
8.4·10–8
–
6.8·102
1.4·103
3.5·104
2.2·10–7
5.0·10–8
4.0·10–9
2.7
2.1
1.6
2.3·1019
1.3·1019
8.5·1018
1.0
1.1
1.3
1.6·10–9
7.9·10–9
1.2·10–7
4. Conclusions
The lowest dark current 3.2·10–6 А/cm2 at the reverse
bias 0.2 V was obtained in p-n junctions produced by
two-stage diffusion of cadmium in n-InSb (100)
substrates at 380 °C for 30 min followed by thermal
annealing at 420 °C for 60 min. In the temperature range
77-150 K the differential resistance-area product at zero
bias is determined by the dark current composed of
diffusion and generation-recombination components
with approximately the same partial contribution.
References
1. А. Rogalskii (Ed.), Infrared Photon Detectors.
SPIE Optical Engineering Press, 1995.
2. A. Rogalski, Optical detectors for focal plane
arrays // Opto-Electron. Rev. 12 (2), p. 221-245
(2004).
3. E. Hurwitz, I.P. Donnely, Planar InSb photodiodes
fabricated by Be and Mg implantation // Solid State
Electron. 18(9), p. 753-756 (1975).
4. V.P. Astahov, D.A. Gindin, V.V. Karpov et al.,
Developments in InSb-photodetectors with very-
low-level dark current for use in high performance
IR CCDs // Prikladnaya Fizika, 2, p. 73-79 (1999),
in Russian.
5. V.P. Astahov, D.A. Gindin, V.V. Karpov,
A.V. Talimov, On the possibility of increasing the
current sensitivity in InSb-based photodiodes //
Prikladnaya Fizika 1, p. 56-62 (2002), in Russian.
6. P.V. Birulin, V.I. Turinov, E.B. Yakimov,
Characteristics of InSb photodiode linear arrays //
Semiconductors (Springer), 38(4), p. 488-503 (2004).
7. H.J. Stocker, Current-voltage characteristics of
alloyed and diffused p-n junction diodes in InSb //
J. Appl. Phys. 32(2), p. 322 (1961).
8. R. Adar, V. Nemirovsky and I. Kidron, Bulk
tunneling contribution to the reverse breakdown
characteristics of InSb gate controlled diodes //
Solid State Electron. 30(12), p. 1289-1293 (1987).
9. S.L. Tu, K.F. Huang and S.J. Yang, InSb p-n
function with avalanche breakdown behavior //
Jpn. J. Appl. Phys. 28(11), p. L1874-L1876 (1989).
10. A.M. Filachev, I.D. Burlakov, A.I. Dirochka et al.,
Fast-operating array photodetective assembly of a
128×128 elements format on the basis of InSb with
the frame-accurate accumulation and function of
the range finder // Prikladnaya Fizika, 2, p. 21-25
(2005), in Russian.
11. M. Moradi, M. Darace, M. Hajian et al., Optimum
concentration of InSb photodiode for minimum low
reverse bias leakage current // Ukr. J. Phys. 55(4),
p. 422-424 (2010).
12. A. Sukach, V. Tetyorkin, A. Voroschenko,
A. Tkachuk et al., Carrier transport mechanisms in
InSb diffusion p-n junctions // Semiconductor
Physics, Quantum Electronics and Optoelectronics,
17(4), p. 325-330 (2014).
13. Indium Antimonide Detectors. Catalog. Teledyne
Judson Technologies, 2015.
14. A.V. Sukach, V.V. Tetyorkin, A.I. Tkachuk,
Carrier transport mechanisms in reverse biased
InSb p-n junctions // Semiconductor Physics,
Quantum Electronics and Optoelectronics, 18(3),
p. 267-271 (2015).
15. V. Tetyorkin, A. Sukach and A. Tkachuk, InAs
infrared photodiodes // Advances in Photodiode. Ed.
Gian-Franco Dalla Betta, INTECH, p. 427-446, 2011.
16. F. Dewald, The kinetics and mechanism of
formation of anode films on single crystal InSb //
J. Electrochem. Soc. 104(4), p. 244-251 (1957).
17. M. Schröder, Semiconductor Materials and Devise
Characterization. Wiley, 2006.
18. Yu.F. Bikovskii, L.A. Vjukov, A.G. Dudoladov
et al., Investigation of MIS film structures based on
CdTe-InSb // Pisma Zhurnal Tekhn. Fiziki, 9(17),
p. 1071-1074 (1983), in Russian.
19. S.M. Sze, Physics of Semiconductors Devices.
Second Edition, Wiley, 1981.
20. B.I. Boltaks, V.I. Sokolov, Investigation of
cadmium diffusion in indium antimonide by layer
autoradiography method // Fizika Tverdogo Tela,
5(4), p. 1077-1081 (1963), in Russian.
|