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.
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.
UV visible-blind and solar-blind 320 × 256 photodiode arrays based on Al
x
Ga
1 –
x
N heteroepitaxial structures (AlGaN HES) and sensitive in the near-ultraviolet range of 0.2–0.4 μm have been ...created and studied. The AlGaN HES were grown by organometallic vapor deposition (MOCVD) and molecular beam epitaxy (MBE) on sapphire substrates. To reduce structural defects, the state of the surface and the surface layer of epipolished sapphire substrates was investigated, and a finishing technology was developed. UV FPAs in the AlGaN HES were produced by ion etching. The dark current components for AlGaN photodiodes were simulated. The main dark current components, such as generation–recombination, shunting leakage, hopping conductivity, and Poole–Frenkel components, are calculated. The possibility of achieving photoelectric parameters on the level of the best foreign counterparts is demonstrated
.
Results of materials science study, which includes a comparative metallographic analysis and fractography of the structure of deformed nickel alloys, are reported; based on these data, the mechanism ...of their high-temperature fracture is revealed. The results of structural analysis are compared with data on the short-term mechanical characteristics of the material at 750°C. It is found that, for the application as a structural material intended for manufacturing and service of products operating in a temperature range of 600–800°C, it is reasonable to use a KhN62MCh2-VI nickel alloy, which exhibits enhanced mechanical properties and is not prone to embrittlement in this temperature range.
The 320 × 256 focal plane arrays based on
р
+
-B–n
-
N
+
tetralayer heterostructures with a wide-gap barrier layer have been investigated. The heterostructures with a narrow-gap
n
-InGaAs absorbing ...layer were grown by means of metalorganic vapor phase epitaxy on InP substrates. The band discontinuity between the In
0.53
Ga
0.47
As absorbing layer and the In
0.52
Al
0.48
As barrier layer is removed by growing a thin four-component
n
-AlInGaAs layer with the bandgap gradient variation. Delta-doped layers included into the heterostructures make it possible to lower the barrier in the valence band and eliminate the nonmonotonicity of energy levels. The experimental study of the dark current has been performed. It has been revealed that the average value of the dark current does not exceed 10 fA for the photodiode arrays with a pitch of 30 μm.
A topical problem of photoelectronics is the development of array photodetector devices of the near infrared spectral range based on the In
x
Ga
1–
x
As/InP epitaxial layers of the megapixel format. ...In this paper, we present the results of studies of current–voltage characteristics of photosensitive elements in arrays of the 320 × 256 format with a step of 30 μm based on heteroepitaxial structures with an InGaAs absorbing layer on InP short-wave infrared substrates. Arrays of photosensitive elements (PSEs) are fabricated using planar, mesa, and mesa planar technologies based on
nB
(Al
0.48
In
0.52
As)
p
-structures. In arrays produced using the mesa planar technology based on
nB
(Al
0.48
In
0.52
As)
p
-structures, small dark current and ampere–watt sensitivity to IR radiation of the 1–1.7 μm range are shown to combine successfully at low bias voltages. Electrophysical parameters of functional layers of initial heteroepitaxial
n-B-p
structures affect efficiently the dark currents and ampere–watt sensitivity of the array elements. Based on these studies, parameters of the
n-B
(Al
0.48
In
0.52
As) functional layers of
p
-structures were optimized and high-efficiency photodiode arrays of the 320 × 256 format with a step of 30 μm and structures of the 640 × 512 format with a step of 15 μm were fabricated with a defectiveness not exceeding 0.5%.
I
–
V
characteristics and spectral photosensitivities of photodiodes based on epitaxially grown hydrides of metal-organic compounds (MOC-hydride epitaxy) of epitaxial structures with the In
0.67
Ga
...0.33
As absorbing layer doped with Zn on the InP substrates are studied. The photodiodes are fabricated using the mesatechnology. The long-wavelength boundary of the spectral photosensitivity of diodes measured at half-maximum is 2.06 μm at room temperature. Photosensitivity spectra are studied in a temperature interval of 230–300 K.
The effect of the properties and materials of a passivation coating and the low-energy argon ion flux on the IâV 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.sub.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.
The results of investigation of profiles formed by ion-beam etching of semiconductor structures through a photolithographic mask are presented. The minimum dimensions of unmasked regions on the ...surfaces of two studied structures are 2 and 5 μm, respectively. It is demonstrated that the etching rate reduces with reduction in the width of the unmasked gap. The effect of reflection of the ion beam from vertical walls formed during etching may be used for fabrication of submicron separating mesaregions.
