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1.
K. D. Maranowski J. M. Peterson S. M. Johnson J. B. Varesi A. C. Childs R. E. Bornfreund A. A. Buell W. A. Radford T. J. de Lyon J. E. Jensen 《Journal of Electronic Materials》2001,30(6):619-622
HgCdTe p-on-n double layer heterojunctions (DLHJs) for mid-wave infrared (MWIR) detector applications have been grown on 100
mm (4 inch) diameter (211) silicon substrates by molecular beam epitaxy (MBE). The structural quality of these films is excellent,
as demonstrated by x-ray rocking curves with full widths at half maximum (FWHMs) of 80–100 arcsec, and etch pit densities
from 1 106 to 7 106 cm−2. Morphological defect densities for these layers are generally less than 1000 cm−2. Improving Hg flux coverage of the wafer during growth can reduce void defects near the edges of the wafers. Improved tellurium
source designs have resulted in better temporal flux stability and a reduction of the center to edge x-value variation from
9% to only 2%. Photovoltaic MWIR detectors have been fabricated from some of these 100mm wafers, and the devices show performance
at 140 K which is comparable to other MWIR detectors grown on bulk CdZnTe substrates by MBE and by liquid phase epitaxy. 相似文献
2.
Molecular-beam epitaxial growth of HgCdTe infrared focal-plane arrays on silicon substrates for midwave infrared applications 总被引:1,自引:0,他引:1
T. J. de Lyon R. D. Rajavel J. A. Vigil J. E. Jensen O. K. Wu C. A. Cockrum S. M. Johnson G. M. Venzor S. L. Bailey I. Kasai W. L. Ahlgren M. S. Smith 《Journal of Electronic Materials》1998,27(6):550-555
Molecular beam epitaxy has been employed to deposit HgCdTe infrared detector structures on Si(112) substrates with performance
at 125K that is equivalent to detectors grown on conventional CdZnTe substrates. The detector structures are grown on Si via
CdTe(112)B buffer layers, whose structural properties include x-ray rocking curve full width at half maximum of 63 arc-sec
and near-surface etch pit density of 3–5 × 105 cm−2 for 9 μm thick CdTe films. HgCdTe p+-on-n device structures were grown by molecular beam epitaxy (MBE) on both bulk CdZnTe and Si with 125K cutoff wavelengths
ranging from 3.5 to 5 μm. External quantum efficiencies of 70%, limited only by reflection loss at the uncoated Si-vacuum
interface, were achieved for detectors on Si. The current-voltage (I-V) characteristics of MBE-grown detectors on CdZnTe and
Si were found to be equivalent, with reverse breakdown voltages well in excess of 700 mV. The temperature dependences of the
I-V characteristics of MBE-grown diodes on CdZnTe and Si were found to be essentially identical and in agreement with a diffusion-limited
current model for temperatures down to 110K. The performance of MBE-grown diodes on Si is also equivalent to that of typical
liquid phase epitaxy-grown devices on CdZnTe with R0A products in the 106–107 Θ-cm2 range for 3.6 μm cutoff at 125K and R0A products in the 104–105 Θ-cm2 range for 4.7 μm cutoff at 125K. 相似文献
3.
Heteroepitaxy of HgCdTe(112) infrared detector structures on Si(112) substrates by molecular-beam epitaxy 总被引:4,自引:0,他引:4
T. J. De Lyon R. D. Rajavel J. E. Jensen O. K. Wu S. M. Johnson C. A. Cockrum G. M. Venzor 《Journal of Electronic Materials》1996,25(8):1341-1346
High-quality, single-crystal epitaxial films of CdTe(112)B and HgCdTe(112)B have been grown directly on Si(112) substrates
without the need for GaAs interfacial layers. The CdTe and HgCdTe films have been characterized with optical microscopy, x-ray
diffraction, wet chemical defect etching, and secondary ion mass spectrometry. HgCdTe/Si infrared detectors have also been
fabricated and tested. The CdTe(112)B films are highly specular, twin-free, and have x-ray rocking curves as narrow as 72
arc-sec and near-surface etch pit density (EPD) of 2 × 106 cm−2 for 8 μm thick films. HgCdTe(112)B films deposited on Si substrates have x-ray rocking curve FWHM as low as 76 arc-sec and
EPD of 3-22 × 106 cm−2. These MBE-grown epitaxial structures have been used to fabricate the first high-performance HgCdTe IR detectors grown directly
on Si without use of an intermediate GaAs buffer layer. HgCdTe/Si infrared detectors have been fabricated with 40% quantum
efficiency and R0A = 1.64 × 104 Ωm2 (0 FOV) for devices with 7.8 μm cutoff wavelength at 78Kto demonstrate the capability of MBE for growth of large-area HgCdTe
arrays on Si. 相似文献
4.
Status of the MBE technology at leti LIR for the manufacturing of HgCdTe focal plane arrays 总被引:2,自引:0,他引:2
P. Ferret J. P. Zanatta R. Hamelin S. Cremer A. Million M. Wolny G. Destefanis 《Journal of Electronic Materials》2000,29(6):641-647
This paper presents recent developments that have been made in Leti Infrared Laboratory in the field of molecular beam epitaxy
(MBE) growth and fabrication of medium wavelength and long wavelength infrared (MWIR and LWIR) HgCdTe devices. The techniques
that lead to growth temperature and flux control are presented. Run to run composition reproducibility is investigated on
runs of more than 15 consecutively grown layers. Etch pit density in the low 105 cm−2 and void density lower than 103 cm−2 are obtained routinely on CdZnTe substrates. The samples exhibit low n-type carrier concentration in the 1014 to 1015 cm−3 range and mobility in excess of 105 cm2/Vs at 77 K for epilayers with 9.5 μm cut-off wavelength. LWIR diodes, fabricated with an-on-p homojunction process present
dynamic resistance area products which reach values of 8 103 Ωcm2 for a biased voltage of −50 mV and a cutoff wavelength of 9.5 μm at 77 K. A 320 × 240 plane array with a 30 μm pitch operating
at 77 K in the MWIR range has been developed using HgCdTe and CdTe layers MBE grown on a Germanium substrate. Mean NEDT value
of 8.8 mK together with an operability of 99.94% is obtained. We fabricated MWIR two-color detectors by the superposition
of layers of HgCdTe with different compositions and a mixed MESA and planar technology. These detectors are spatially coherent
and can be independently addressed. Current voltage curves of 60 × 60 μm2 photodiodes have breakdown voltage exceeding 800 mV for each diode. The cutoff wavelength at 77 K is 3.1 μm for the MWIR-1
and 5 μm for the MWIR-2. 相似文献
5.
Direct growth of CdZnTe/Si substrates for large-area HgCdTe infrared focal plane arrays 总被引:1,自引:0,他引:1
S. M. Johnson T. J. de Lyon C. A. Cockrum W. J. Hamilton T. Tung F. I. Gesswein B. A. Baumgratz L. M. Ruzicka O. K. Wu J. A. Roth 《Journal of Electronic Materials》1995,24(5):467-473
Direct epitaxial growth of high-quality 100lCdZnTe on 3 inch diameter vicinal {100}Si substrates has been achieved using molecular
beam epitaxy (MBE); a ZnTe initial layer was used to maintain the {100} Si substrate orientation. The properties of these
substrates and associated HgCdTe layers grown by liquid phase epitaxy (LPE) and subsequently processed long wavelength infrared
(LWIR) detectors were compared directly with our related efforts using CdZnTe/ GaAs/Si substrates grown by metalorganic chemical
vapor deposition (MOCVD). The MBE-grown CdZnTe layers are highly specular and have both excellent thickness and compositional
uniformity. The x-ray full-width at half-maximum (FWHM) of the MBE-grown CdZnTe/Si increases with composition, which is a
characteristic of CdZnTe grown by vapor phase epitaxy, and is essentially equivalent to our results obtained on CdZnTe/GaAs/Si.
As we have previously observed, the x-ray FWHM of LPE-grown HgCdTe decreases, particularly for CdZnTe compositions near the
lattice matching condition to HgCdTe; so far the best value we have achieved is 54 arc-s. Using these MBE-grown substrates,
we have fabricated the first high-performance LWIR HgCdTe detectors and 256 x 256 arrays using substrates consisting of CdZnTe
grown directly on Si without the use of an intermediate GaAs buffer layer. We find first that there is no significant difference
between arrays fabricated on either CdZnTe/Si or CdZnTe/GaAs/Si and second that the results on these Si-based substrates are
comparable with results on bulk CdZnTe substrates at 78K. Further improvements in detector performance on Si-based substrates
require a decrease in the dislocation density. 相似文献
6.
R. D. Rajavel D. Jamba O. K. Wu J. A. Roth P. D. Brewer J. E. Jensen C. A. Cockrum G. M. Venzor S. M. Johnson 《Journal of Electronic Materials》1996,25(8):1411-1415
A robust process has been developed for the reproducible growth of in-situ doped Hg1−xCdxTe:As alloys by molecular beam epitaxy. Net hole concentrations in excess of 5 x 1017 cm−3, with peak mobilities >200 cm2/Vs were measured in Hg0.74Cd0.26Te:As films. The p-type layers were twin-free and consistently exhibit narrow x-ray rocking curves (<40 arc sec). The reproducible
growth of small lots of p-on-n LWIR detector structures has been established. For a typical lot consisting of 13 layers, the
average x-value of the n-type base layer was 0.226 with a standard deviation of 0.003. The lateral compositional uniformity
across a 2.5 cm × 2.5 cm wafer was × = +- 0.0006. High performance p-on-n LWIR diodes were fabricated that exhibited RoAo values (0-fov at 78K) as large as 350 Q cm2 at 10.4 μm. 相似文献
7.
G. Destéfanis A. Astier J. Baylet P. Castelein J. P. Chamonal E. DeBorniol O. Gravand F. Marion J. L. Martin A. Million P. Rambaud F. Rothan J. P. Zanatta 《Journal of Electronic Materials》2003,32(7):592-601
In this article, we present recent developments of the research in France at LETI infrared laboratory in the field of complex
third-generation HgCdTe IRCMOS focal plane arrays (FPAs). We illustrate this with three prototypes of FPAs made at LETI, which
have involved some technological improvements from the standard process today in production at Sofradir. We present, using
molecular-beam epitaxy (MBE) growth, a 128 × 128 dual-band infrared (photodetector)-complementary metal oxide semiconductor
(IRCMOS) with a pitch of 50 μm operating within 2–5 μm. Using the more conventional liquid-phase epitaxy (LPE) growth, we
show a new generation of high-performance long linear arrays (1500 × 2; pitch, 30 μm) operating in medium-wavelength infrared
(MWIR) or long-wavelength infrared (LWIR) bands based on a modular architecture of butted HgCdTe detection circuit and SiCMOS
multiplexers. Finally, we present for the first time a megapixel (1000 × 1000) FPA with a pitch of 15 μm operating in the
MWIR band that exhibits a very high performance and pixel operability. 相似文献
8.
S. M. Johnson A. A. Buell M. F. Vilela J. M. Peterson J. B. Varesi M. D. Newton G. M. Venzor R. E. Bornfreund W. A. Radford E. P. G. Smith J. P. Rosbeck T. J. De Lyon J. E. Jensen V. Nathan 《Journal of Electronic Materials》2004,33(6):526-530
The heteroepitaxial growth of HgCdTe on large-area Si substrates is an enabling technology leading to the production of low-cost,
large-format infrared focal plane arrays (FPAs). This approach will allow HgCdTe FPA technology to be scaled beyond the limitations
of bulk CdZnTe substrates. We have already achieved excellent mid-wavelength infrared (MWIR) and short wavelength infrared
(SWIR) detector and FPA results using HgCdTe grown on 4-in. Si substrates using molecular beam epitaxy (MBE), and this work
was focused on extending these results into the long wavelength infrared (LWIR) spectral regime. A series of nine p-on-n LWIR
HgCdTe double-layer heterojunction (DLHJ) detector structures were grown on 4-in. Si substrates. The HgCdTe composition uniformity
was very good over the entire 4-in. wafer with a typical maximum nonuniformity of 2.2% at the very edge of the wafer; run-to-run
composition reproducibility, realized with real-time feedback control using spectroscopic ellipsometry, was also very good.
Both secondary ion mass spectrometry (SIMS) and Hall-effect measurements showed well-behaved doping and majority carrier properties,
respectively. Preliminary detector results were promising for this initial work and good broad-band spectral response was
demonstrated; 61% quantum efficiency was measured, which is very good compared to a maximum allowed value of 70% for a non-antireflection-coated
Si surface. The R0A products for HgCdTe/Si detectors in the 9.6-μm and 12-μm cutoff range were at least one order of magnitude below typical
results for detectors fabricated on bulk CdZnTe substrates. This lower performance was attributed to an elevated dislocation
density, which is in the mid-106 cm−2 range. The dislocation density in HgCdTe/Si needs to be reduced to <106 cm−2 to make high-performance LWIR detectors, and multiple approaches are being tried across the infrared community to achieve
this result because the technological payoff is significant. 相似文献
9.
J. Baylet P. Ballet P. Castelein F. Rothan O. Gravrand M. Fendler E. Laffosse J. P. Zanatta J. P. Chamonal A. Million G. Destefanis 《Journal of Electronic Materials》2006,35(6):1153-1158
The purpose of this paper is to present the electro-optical performances of dual-band infrared detectors operating in a fully
spatially coherent mode, with a small pixel pitch. The successive steps of device fabrication are first exposed, including
molecular beam epitaxy (MBE), technological processing, and readout circuit design. It is shown that very high-quality multiple
layer heterostructures of HgCdTe can be grown and processed into 256×256 arrays of 25-μm pitch mesas, each mesa including
two photodiodes with different cutoff wavelengths ranging in the midwave infrared (MWIR). Characterization of these focal
plane arrays (FPAs) shows very good homogeneity, low defect density, and operabilities usually above 99% for both response
and noise equivalent thermal difference (NETD). 相似文献
10.
Li He Xiangliang Fu Qingzhu Wei Weiqiang Wang Lu Chen Yan Wu Xiaoning Hu Jianrong Yang Qinyao Zhang Ruijun Ding Xiaoshuang Chen Wei Lu 《Journal of Electronic Materials》2008,37(9):1189-1199
Results of first-principles calculations and experiments focusing on molecular beam epitaxy (MBE) growth of HgCdTe on the
alternative substrates of GaAs and Si are described. The As passivation on (2 × 1) reconstructed (211) Si and its effects
on the surface polarity of ZnTe or CdTe were clarified by examining the bonding configurations of As. The quality of HgCdTe
grown on Si was confirmed to be similar to that grown on GaAs. Typical surface defects in HgCdTe and CdTe were classified.
Good results for uniformities of full width at half maximum (FWHM) values of x-ray rocking curves, surface defects, and x values of Hg1−x
Cd
x
Te were obtained by refining the demanding parameters and possible tradeoffs. The sticking coefficient of As4 for MBE HgCdTe was determined. The effects of Hg-assisted annealing for As activation were investigated experimentally and
theoretically by examining the difference of the formation energy of AsHg and AsTe. Results of focal-plane arrays (FPAs) fabricated with HgCdTe grown on Si and on GaAs are discussed. 相似文献
11.
P. S. Wijewarnsuriya M. Zandian D. D. Edwall W. V. McLevige C. A. Chen J. G. Pasko G. Hildebrandt A. C. Chen J. M. Arias A. I. D’Souza S. Rujirawat S. Sivananthan 《Journal of Electronic Materials》1998,27(6):546-549
The capability of growing state-of-the-art middle wavelength infrared (MWIR)-HgCdTe layers by molecular beam epitaxy (MBE)
on large area silicon substrates has been demonstrated. We have obtained excellent compositional uniformity with standard
deviation of 0.001 with mean composition of 0.321 across 1.5″ radii. R0A as high as 5 × 107 ω-cm2 with a mean value of 7 × 106 Θ-cm2 was measured for cut-off wavelength of 4.8 μm at 77K. Devices exhibit diffusion limited performance for temperatures above
95K. Quantum efficiencies up to 63% were observed (with no anti-reflection coating) for cut-off wavelength (4.8–5.4) μm @
77K. Excellent performance of the fabricated photodiodes on MBE HgCdTe/CdTe/Si reflects on the overall quality of the grown
material in the MWIR region. 相似文献
12.
G. Brill S. Velicu P. Boieriu Y. Chen N. K. Dhar T. S. Lee Y. Selamet S. Sivananthan 《Journal of Electronic Materials》2001,30(6):717-722
The traditional substrate of choice for HgCdTe material growth has been lattice matched bulk CdZnTe material. However, as
larger array sizes are required for future devices, it is evident that current size limitations of bulk substrates will become
an issue and therefore large area Si substrates will become a requirement for HgCdTe growth in order to maintain the cost-efficiency
of future systems. As a result, traditional substrate mounting methods that use chemical compounds to adhere the substrate
to the substrate holder may pose significant technical challenges to the growth and fabrication of HgCdTe on large area Si
substrates. For these reasons, non-contact (indium-free) substrate mounting was used to grow mid-wave infrared (MWIR) HgCdTe
material on 3″ CdTe/Si substrates. In order to maintain a constant tepilayer temperature during HgCdTe nucleation, reflection
high-energy electron diffraction (RHEED) was implemented to develop a substrate temperature ramping profile for HgCdTe nucleation.
The layers were characterized ex-situ using Fourier transform infrared (FTIR) and etch pit density measurements to determine
structural characteristics. Dislocation densities typically measured in the 9 106 cm−2 to 1 107 cm−2 range and showed a strong correlation between ramping profile and Cd composition, indicating the uniqueness of the ramping
profiles. Hall and photoconductive decay measurements were used to characterize the electrical properties of the layers. Additionally,
both single element and 32 32 photovoltaic devices were fabricated from these layers. A RA value of 1.8 106-cm2 measured at −40 mV was obtained for MWIR material, which is comparable to HgCdTe grown on bulk CdZnTe substrates. 相似文献
13.
High-quality large-area MBE HgCdTe/Si 总被引:2,自引:0,他引:2
J. M. Peterson J. A. Franklin M. Reddy S. M. Johnson E. Smith W. A. Radford I. Kasai 《Journal of Electronic Materials》2006,35(6):1283-1286
HgCdTe offers significant advantages over other similar semiconductors, which has made it the most widely utilized variable-gap
material in infrared (IR) focal plane array (FPA) technology. HgCdTe hybrid FPAs consisting of two-dimensional detector arrays
that are hybridized to Si readout circuits (ROIC) are the dominant technology for second-generation infrared systems. However,
one of the main limitations of the HgCdTe materials system has been the size of lattice-matched bulk CdZnTe substrates, used
for epitaxially grown HgCdTe, which have been limited to 30 cm2 in production. This size limitation does not adequately support the increasing demand for larger FPA formats which now require
sizes up to 2048×2048, and only a single die can be printed per wafer. Heteroepitaxial Si-based substrates offer a cost-effective
technology that can be scaled to large wafer sizes and further offer a thermal-expansion-matched hybrid structure that is
suitable for large format FPAs. This paper presents data on molecular-beam epitaxy (MBE)-grown HgCdTe/Si wafers with much
improved materials characteristics than previously reported. We will present data on 4- and 6-in diameter HgCdTe both with
extremely uniform composition and extremely low defects. Large-diameter HgCdTe/Si with nearly perfect compositional uniformity
and ultra low defect density is essential for meeting the demanding specifications of large format FPAs. 相似文献
14.
HgCdTe focal plane arrays for dual-color mid- and long-wavelength infrared detection 总被引:1,自引:0,他引:1
E. P. G. Smith L. T. Pham G. M. Venzor E. M. Norton M. D. Newton P. M. Goetz V. K. Randall A. M. Gallagher G. K. Pierce E. A. Patten R. A. Coussa K. Kosai W. A. Radford L. M. Giegerich J. M. Edwards S. M. Johnson S. T. Baur J. A. Roth B. Nosho T. J. De Lyon J. E. Jensen R. E. Longshore 《Journal of Electronic Materials》2004,33(6):509-516
Raytheon Vision Systems (RVS, Goleta, CA) in collaboration with HRL Laboratories (Malibu, CA) is contributing to the maturation
and manufacturing readiness of third-generation, dual-color, HgCdTe infrared staring focal plane arrays (FPAs). This paper
will highlight data from the routine growth and fabrication of 256×256 30-μm unit-cell staring FPAs that provide dual-color
detection in the mid-wavelength infrared (MWIR) and long wavelength infrared (LWIR) spectral regions. The FPAs configured
for MWIR/MWIR, MWIR/LWIR, and LWIR/LWIR detection are used for target identification, signature recognition, and clutter rejection
in a wide variety of space and ground-based applications. Optimized triple-layer heterojunction (TLHJ) device designs and
molecular beam epitaxy (MBE) growth using in-situ controls has contributed to individual bands in all dual-color FPA configurations
exhibiting high operability (>99%) and both performance and FPA functionality comparable to state-of-the-art, single-color
technology. The measured spectral cross talk from out-of-band radiation for either band is also typically less than 10%. An
FPA architecture based on a single-mesa, single-indium bump, and sequential-mode operation leverages current single-color
processes in production while also providing compatibility with existing second-generation technologies. 相似文献
15.
S. Velicu T. S. Lee C. H. Grein P. Boieriu Y. P. Chen N. K. Dhar J. Dinan D. Lianos 《Journal of Electronic Materials》2005,34(6):820-831
The cost and performance of hybrid HgCdTe infrared (IR) focal plane arrays are constrained by the necessity of fabricating
the detector arrays on a CdZnTe substrate. These substrates are expensive, fragile, available only in small rectangular formats,
and are not a good thermal expansion match to the silicon readout integrated circuit. We discuss in this paper an IR sensor
technology based on monolithically integrated IR focal plane arrays that could replace the conventional hybrid focal plane
array technology. We have investigated the critical issues related to the growth of HgCdTe on Si read-out integrated circuits
and the fabrication of monolithic focal plane arrays: (1) the design of Si read-out integrated circuits and focal plane array
layouts; (2) the low-temperature cleaning of Si(001) wafers; (3) the growth of CdTe and HgCdTe layers on read-out integrated
circuits; (4) diode creation, delineation, electrical, and interconnection; and (4) demonstration of high yield photovoltaic
operation without limitation from earlier preprocessing such as substrate cleaning, molecular beam epitaxy (MBE) growth, and
device fabrication. Crystallographic, optical, and electrical properties of the grown layers will be presented. Electrical
properties for diodes fabricated on misoriented Si and readout integrated circuit (ROIC) substrates will be discussed. The
fabrication of arrays with demonstrated I–V properties show that monolithic integration of HgCdTe-based IR focal plane arrays
on Si read-out integrated circuits is feasible and could be implemented in the third generation of IR systems. 相似文献
16.
L. O. Bubulac W. E. Tennant J. G. Pasko L. J. Kozlowski M. Zandian M. E. Motamedi R. E. De Wames J. Bajaj N. Nayar W. V. McLevige N. S. Gluck R. Melendes D. E. Cooper D. D. Edwall J. M. Arias R. Hall A. I. D’souza 《Journal of Electronic Materials》1997,26(6):649-655
Short wave infrared (SWIR) devices have been fabricated using Rockwell’s double layer planar heterostructure (DLPH) architecture
with arsenic-ion implanted junctions. Molecular beam epitaxially grown HgCdTe/CdZnTe multilayer structures allowed the thin,
tailored device geometries (typical active layer thickness was ∼3.5 μm and cap layer thickness was ∼0.4 μm) to be grown. A
planar-mesa geometry that preserved the passivation advantages of the DLPH structure with enhanced optical collection improved
the performance. Test detectors showed Band 7 detectors performing near the radiative limit (∼3-5X below theory). Band 5 detector
performance was ∼4-50X lower than radiative limited performance, apparently due to Shockley-Hall-Read recombination. We have
fabricated SWIR HgCdTe 256 × 12 × 2 arrays of 45 um × 45 μm detector on 45 μm × 60 μm centers and with cutoff wavelength which
allows coverage of the Landsat Band 5 (1.5−1.75 μm) and Landsat Band 7 (2.08−2.35 μm) spectral regions. The hybridizable arrays
have four subarrays, each having a different detector architecture. One of the Band 7 hybrids has demonstrated performance
approaching the radiative theoretical limit for temperatures from 250 to 295K, consistent with test results. D* performance
at 250K of the best subarray was high, with an operability of ∼99% at 1012 cm Hz1/2/W at a few mV bias. We have observed 1/f noise below 8E-17 AHz 1/2 at 1 Hz. Also for Band 7 test structures, Ge thin film diffractive microlenses fabricated directly on the back side of the
CdZnTe substrate showed the ability to increase the effective collection area of small (nominally <20 μm μm) planar-mesa diodes
to the microlens size of 48 urn. Using microlenses allows array performance to exceed 1-D theory up to a factor of 5. 相似文献
17.
This paper describes our progress to improve the material quality, reproducibility, and flexibility of molecular beam epitaxial
(MBE) growth of HgCdTe. Data, statistics, and yields according to defined screen criteria are presented for n-type layer carrier
concentration and mobility, void defect density, and dislocation density for more than 100 layers. Minority carrier lifetime
data are also presented. Continued improvements in impurity reductiont have allowed us to achieve, for the first time, reproducible,
low n-type carrier concentration in the mid-1014 cnr−3 range with high electron mobility. Data are presented that show that low dislocation density films are obtained for growth
on CdZnTe substrates with a wide range of Zn concentration. Results are presented from a nine-growth run first pass success
demonstration run to further assess material quality reproducibility and flexibility of wavelength band tuning. These results
demonstrate the promising potential of MBE growth for flexible manufacturing of HgCdTe for infrared focal plane arrays. 相似文献
18.
Heteroepitaxy of HgCdTe (211)B on Ge substrates by molecular beam epitaxy for infrared detectors 总被引:3,自引:0,他引:3
J. P. Zanatta P. Ferret G. Theret A. Million M. Wolny J. P. Chamonal G. Destefanis 《Journal of Electronic Materials》1998,27(6):542-545
Epitaxial growth of (211)B CdTe/HgCdTe has been achieved on two inch germanium (Ge) by molecular beam epitaxy (MBE). Germanium
was chosen as an alternative substrate to circumvent the weaknesses of CdZnTe wafers. The ease of surface preparation makes
Ge an attractive candidate among many other alternative substrates. Best MBE CdTe growth results were obtained on (211) Ge
surfaces which were exposed to arsenic and zinc fluxes prior to the MBE growth. This surface preparation enabled CdTe growth
with B-face crystallographic polarity necessary for the HgCdTe growth. This process was reproducible, and produced a smooth
and mirror-like surface morphology. The best value of the {422} x-ray double diffraction full width at half maximum measured
from the HgCdTe layer was 68 arc-s. We present the 486 point maps of FWHM statistical values obtained from CdTe/Ge and HgCdTe/CdTe/Ge.
High resolution microscopy electron transmission and secondary ion mass spectroscopy characterization results are also presented
in this paper. High-performance middle wavelength infrared HgCdTe 32-element photodiode linear arrays, using the standard
LETI/LIR planar n-on-p ion implanted technology, were fabricated on CdTe/Ge substrates. At 78K, photodiodes exhibited very
high R0A figure of merit higher than 106 Ωcm−2 for a cutoff wavelength of 4.8 μm. Excess low frequency noise was not observed below 150K. 相似文献
19.
D. D. Edwall D. B. Young A. C. Chen M. Zandian J. M. Arias Brian Dlugosch Scott Priddy 《Journal of Electronic Materials》1999,28(6):740-742
Initial results using a valved Te source for molecular beam epitaxial growth of Hg1−xCdxTe are described. Unlike the case for a conventional Knudsen effusion cell where the flux is controlled primarily by temperature,
flux from the valved source is controlled primarily by a variable orifice capable of good closure so that the cell temperature
can be fixed at the operating temperature. Operating characteristics of the source are described, and include being able to
nearly instantaneously change the flux magnitude at will. Using the source for HgCdTe growth has resulted in promising composition
reproducibility improvement in initial growth runs. 相似文献
20.
J. P. Zanatta G. Badano P. Ballet C. Largeron J. Baylet O. Gravrand J. Rothman P. Castelein J. P. Chamonal A. Million G. Destefanis S. Mibord E. Brochier P. Costa 《Journal of Electronic Materials》2006,35(6):1231-1236
The Leti-Lir has studied II–VI compounds for infrared (IR) detection for more than 20 years. The need to reduce the production
cost of IR focal plane arrays (FPAs) sparked the development of heteroepitaxy on large-area substrates. Germanium has been
chosen as the heterosubstrate for the third generation of IR detectors. First, we report on the progress achieved in HgCdTe
growth on 3-in. and 4-in. (211)B CdTe/Ge. Then, we discuss the choice of a new machine for larger size and better homogeneity.
Finally, we present the latest results on third-generation IR multicolor and megapixel devices. First-time results regarding
a middle wavelength infrared (MWIR) dual-band FPA, with a reduced pitch of 25 μm, and a MWIR 1,280×1,024 FPA will be shown.
Both detectors are based on molecular beam epitaxy (MBE)-grown HgCdTe on Ge. The results shown validate the choice of Ge as
the substrate for third-generation detectors. 相似文献