Multilayer structures based on semiconductor materials of the antimonide group with InSb and Al
x
In
1 –
x
Sb absorbing layers, including structures with an InAlSb barrier layer (InSb/InAlSb/InSb), ...designed for the manufacturing of advanced photodetectors (PDs) that detect radiation in the mid-wave infrared (IR) range. On the basis of
p
–
i
–
n
and barrier structures grown by the MBE method, photosensitive elements (PSEs) of various topologies with InSb and Al
x
In
1 –
x
Sb absorbing layers were fabricated. It is shown that wide-gap Al
x
In
1 –
x
Sb ternary solutions, which detect radiation in the medium-wavelength region of the spectrum, are an alternative to the narrow-gap binary compound InSb, because, due to the wide-gap, photodiodes based on Al
x
In
1 –
x
Sb have lower currents and, therefore, noise. The average values of detectivity
D
* and noise-equivalent temperature difference (NETD) have been measured for various topology photodetectors, so
D
* was more than 10
11
cm W
–1
Hz
1/2
in
p
–
i
–
n
structures, and
D
* exceed of 10
12
cm W
–1
Hz
1/2
in barrier structures.
In this paper, we analyze the design features of avalanche photodiode architectures with separated absorption (InGaAs) and multiplication (InAlAs) regions. Two architectures are considered:
p
+
...–M–с–i–n
+
-
and
p
+
–i–с–M–n
+
-
types implemented in InGaAs/InAlAs/InP heteroepitaxial structures (HES). Three main layers, absorbing (
i
), charge (
c
), and multiplying (
M
), were mandatory for each architecture. Matrices of photosensitive elements were formed using data from InGaAs/InAlAs/InP HES grown via MOS hydride epitaxy (MOSHE) method. Photocurrent multiplication factors, which varied from 1 to 18–25 in the range of reverse bias voltages of
U
= 8–14 V, were calculated based on the studied current–voltage characteristics of avalanche elements in the matrices.
We report on the investigations of focal plane arrays for mid-wave infrared radiation detection based on antimonide multilayers with InSb, Al
x
In
1 –
x
Sb, and InAs
1 –
x
Sb
x
absorption layers, ...including structures with InAlSb (InSb/InAlSb/InSb) and InAsSb (InAsSb/AlAsSb/InAsSb) barrier layers for optoelectronic systems and equipment. Photosensitive elements of different topologies have been fabricated. It has been demonstrated that wideband Al
x
In
1-x
Sb and InAs
1 –
x
Sb
x
ternary alloys are an alternative to the narrowband InSb binary compound, since the photodiodes based on them exhibit lower dark currents and, consequently, low noise. The average values of detectivity
D
* and noise equivalent temperature difference for the photodetectors based on photosensitive element arrays of different topologies have been measured.
Methods for increasing mechanical strength and reproducibility in the design of dual-spectral thinned matrix photodetectors made of InSb by sputtering multilayer interference coatings based on layers ...of silicon and silicon dioxide are considered. The results of modeling the distribution of mechanical stresses and suppression of errors in the optical thickness of antireflection coatings with different numbers of layers are presented. Experimental samples of dual-spectral matrix photodetectors were obtained, confirming the simulation results.
Methods for measuring the current-voltage characteristics (
I–V
curves) of photodiodes in a 6 × 576 mercury-cadmium-tellurium (MCT) multirow photodetector designed for operation in the longwave part ...of the infrared (IR) spectral range are analyzed. The
I–V
curve is plotted using the resultes of measurements of output signals of a large-scale readout integrated circuit (ROIC) hybridized with a row of IR photodiodes. The method of independent current measurement at each point of the
I–V
curve is compared to the method of additive current measurements. A method of determining optimum working points of photodiodes by plotting and analyzing the dependence of the differential resistance of photodiode on the bias voltage is proposed. Distributions of photodiode currents for a sample of a 6 × 576-element focal plane array (FPA) based on MCT photodiodes with a
p
-type conductivity substrate having the cutoff wavelength of λ
0.5
= 10.5 μm are considered.
The effect of the properties and materials of a passivation coating and the low-energy argon ion flux on the
I‒V
characteristics of the
XBn
-InGaAs focal plane arrays has been studied. Passivation ...coatings have been obtained by magnetron and resistive sputtering of dielectric materials (zinc sulfide ZnS, silicon monoxide SiO, and yttrium fluoride YF
3
). It is shown that the exposure to low-energy argon ions leads to a catastrophic increase in the dark currents in non-passivated array elements.
MBE-grown InSb photodetector arrays Bakarov, A. K.; Gutakovskii, A. K.; Zhuravlev, K. S. ...
Technical physics,
06/2017, Letnik:
62, Številka:
6
Journal Article
Recenzirano
The MBE method has been applied to grow InSb layers on InSb substrates. These layers have served as a basis for fabricating mid-wave IR photodetector arrays. The characteristics of photodetector ...arrays on epitaxial InSb layers have been compared with those of series-produced single-crystal InSb arrays.
The photoelectric interconnection of matrix photodetectors in the medium-wave IR range of 320 × 256 elements with a step of 30 μm and 640 × 512 elements with a step of 15 μm based on indium ...antimonide is investigated. The dependence of the crosstalk value on the thickness of a thinned InSb bulk structure was determined. The interrelation of the elements of matrix photodetectors based on epitaxial indium antimonide is significantly less than the interrelation based on bulk indium antimonide.
In this study we investigated the dependences of the rate of ion-beam etching of the upper contact layer (GaAs:Si), an active region consisting of a 50-fold alternation of barrier layers (Al
x
Ga
1–
...x
As) and quantum wells (GaAs:Si) and the lower contact layer (GaAs:Si) along the depth of QWIP structures based on GaAs–AlGaAs, fabricated by molecular beam epitaxy (MBE), in order to determine the effect of the composition of various layers on the etching rate and the ability to complete the etching process to the desired depth in time.
Photoelectric characteristics of a 320 × 256-element focal plane array (FPA) with a pitch of 30 μm, whose photosensitive element is formed in the InSb epitaxial layer deposited on a heavily doped ...substrate, have been investigated. For a relative aperture of 1: 0.94 and an integration time of 1.46 ms, the mean value of the noise-equivalent temperature difference is 10.5 mK, the percentage of defective elements is 0.12%, and the correction time is more than 3 h. The FPA has been compared to similar commercial devices based on bulk InSb.
