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1.
E. A. Patten P. M. Goetz M. F. Vilela K. Olsson D. D. Lofgreen J. G. Vodicka S. M. Johnson 《Journal of Electronic Materials》2010,39(10):2215-2219
HgCdTe grown on large-area Si substrates allows for larger array formats and potentially reduced focal-plane array (FPA) cost
compared with smaller, more expensive CdZnTe substrates. The goal of this work is to evaluate the use of HgCdTe/Si for mid-wavelength/long-wavelength
infrared (MWIR/LWIR) dual-band FPAs. A series of MWIR/LWIR dual-band HgCdTe triple-layer n-P-n heterojunction (TLHJ) device structures were grown by molecular-beam epitaxy (MBE) on 100-mm (211)Si substrates. The wafers
showed low macrodefect density (<300 cm−2) and was processed into 20-μm-unit-cell 640 × 480 detector arrays which were mated to dual-band readout integrated circuits (ROICs) to produce FPAs. The
measured 80-K cutoff wavelengths were 5.5 μm for MWIR and 9.4 μm for LWIR, respectively. The FPAs exhibited high pixel operabilities in each band, with noise equivalent differential temperature
(NEDT) operabilities of 99.98% for the MWIR band and 99.6% for the LWIR band demonstrated at 84 K. 相似文献
2.
Status of LWIR HgCdTe-on-Silicon FPA Technology 总被引:1,自引:0,他引:1
M. Carmody J.G. Pasko D. Edwall E. Piquette M. Kangas S. Freeman J. Arias R. Jacobs W. Mason A. Stoltz Y. Chen N.K. Dhar 《Journal of Electronic Materials》2008,37(9):1184-1188
The use of silicon as an alternative substrate to bulk CdZnTe for epitaxial growth of HgCdTe for infrared detector applications
is attractive because of potential cost savings as a result of the large available sizes and the relatively low cost of silicon
substrates. However, the potential benefits of silicon as a substrate have been difficult to realize because of the technical
challenges of growing low-defect-density HgCdTe on silicon where the lattice mismatch is ∼19%. This is especially true for
long-wavelength infrared (LWIR) HgCdTe detectors where the performance can be limited by the high (∼5 × 106 cm−2) dislocation density typically found in HgCdTe grown on silicon. The current status of LWIR (9 μm to 11 μm at 78 K) HgCdTe on silicon focal-plane arrays (FPAs) is reviewed. Recent progress is covered including improvements in noise
equivalent differential temperature (NEDT) and array operability. NEDT of <25 mK and NEDT operability >99% are highlighted
for 640 × 480 pixel, 20-μm-pitch FPAs. 相似文献
3.
M.F. Vilela D.D. Lofgreen E.P.G. Smith M.D. Newton G.M. Venzor J.M. Peterson J.J. Franklin M. Reddy Y. Thai E.A. Patten S.M. Johnson M.Z. Tidrow 《Journal of Electronic Materials》2008,37(9):1465-1470
Long-wavelength infrared (LWIR) HgCdTe p-on-n double-layer heterojunctions (DLHJs) for infrared detector applications have been grown on 100 mm Ge (112) substrates by
molecular beam epitaxy (MBE). The objective of this current work was to grow our baseline p-on-n DLHJ detector structure (used earlier on Si substrates) on 100 mm Ge substrates in the 10 μm to 11 μm LWIR spectral region, evaluate the material properties, and obtain some preliminary detector performance data. Material
characterization techniques included are X-ray rocking curves, etch pit density (EPD) measurements, compositional uniformity
determined from Fourier-transform infrared (FTIR) transmission, and doping concentrations determined from secondary-ion mass
spectroscopy (SIMS). Detector properties include resistance-area product (RoA), spectral response, and quantum efficiency.
Results of LWIR HgCdTe detectors and test structure arrays (TSA) fabricated on both Ge and silicon (Si) substrates are presented
and compared. Material properties demonstrated include X-ray full-width of half-maximum (FWHM) as low as 77 arcsec, typical
etch pit densities in mid 106 cm−2 and wavelength cutoff maximum/minimum variation <2% across the full wafer. Detector characteristics were found to be nearly
identical for HgCdTe grown on either Ge or Si substrates. 相似文献
4.
M. Reddy J. M. Peterson D. D. Lofgreen T. Vang E. A. Patten W. A. Radford S. M. Johnson 《Journal of Electronic Materials》2010,39(7):974-980
This paper describes molecular-beam epitaxy growth of mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) dual-band
device structures on large-area (6 cm × 6 cm) CdZnTe substrates. Wafer-level composition and defect mapping techniques were
used to investigate the limiting mechanisms in improving the cutoff wavelength (λ
c) uniformity and reducing the defect density. Structural quality of epitaxial layers was monitored using etch pit density
(EPD) measurements at various depths in the epitaxial layers. Finally, 640 × 480, 20-μm-pixel-pitch dual-band focal-plane arrays (FPAs) were fabricated to demonstrate the overall maturity of growth and fabrication
processes of epitaxial layers. The MWIR/LWIR dual-band layers, at optimized growth conditions, show a λ
c variation of ±0.15 μm across a 6 cm × 6 cm CdZnTe substrate, a uniform low macrodefect density with an average of 1000 cm−2, and an average EPD of 1.5 × 105 cm−2. FPAs fabricated using these layers show band 1 (MWIR) noise equivalent temperature difference (NETD) operability of 99.94%
and band 2 (LWIR) NETD operability of 99.2%, which are among the highest reported to date. 相似文献
5.
Molecular beam epitaxy grown long wavelength infrared HgCdTe on Si detector performance 总被引:1,自引:0,他引:1
M. Carmody J. G. Pasko D. Edwall R. Bailey J. Arias S. Cabelli J. Bajaj L. A. Almeida J. H. Dinan M. Groenert A. J. Stoltz Y. Chen G. Brill N. K. Dhar 《Journal of Electronic Materials》2005,34(6):832-838
The use of silicon as a substrate alternative to bulk CdZnTe for epitaxial growth of HgCdTe for infrared (IR) detector applications
is attractive because of potential cost savings as a result of the large available sizes and the relatively low cost of silicon
substrates. However, the potential benefits of silicon as a substrate have been difficult to realize because of the technical
challenges of growing low defect density HgCdTe on silicon where the lattice mismatch is ∼19%. This is especially true for
LWIR HgCdTe detectors where the performance can be limited by the high (∼5×106 cm−2) dislocation density typically found in HgCdTe grown on silicon. We have fabricated a series of long wavelength infrared
(LWIR) HgCdTe diodes and several LWIR focal plane arrays (FPAs) with HgCdTe grown on silicon substrates using MBE grown CdTe
and CdSeTe buffer layers. The detector arrays were fabricated using Rockwell Scientific’s planar diode architecture. The diode
and FPA and results at 78 K will be discussed in terms of the high dislocation density (∼5×106 cm2) typically measured when HgCdTe is grown on silicon substrates. 相似文献
6.
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
7.
M. F. Vilela A. A. Buell M. D. Newton G. M. Venzor A. C. Childs J. M. Peterson J. J. Franklin R. E. Bornfreund W. A. Radford S. M. Johnson 《Journal of Electronic Materials》2005,34(6):898-904
Middle wave infrared (MWIR) HgCdTe p-on-n double-layer heterojunctions (DLHJs) for infrared detector applications have been
grown on 100-mm Si (112) substrates by molecular beam epitaxy (MBE) for large format 2,560×512 focal plane arrays (FPAs).
In order to meet the performance requirements needed for these FPAs, cutoff and doping uniformity across the 100-mm wafer
are crucial. Reflection high-energy electron diffraction (RHEED), secondary ion mass spectrometry (SIMS), Fourier transform
infrared spectrometry (FTIR), x-ray, and etch pit density (EPD) were monitored to assess the reproducibility, uniformity,
and quality of detector material grown. Material properties demonstrated include x-ray full width half maximum (FWHM) as low
as 64 arc-sec, typical etch pit densities in mid-106 cm−2, cutoff uniformity below 5% across the full wafer, and typical density of macrodefects <1000 cm−2. The detector quality was established by using test structure arrays (TSAs), which include miniarray diodes with the similar
pitch as the detector array for easy measurement of critical parameters such as diode I-V characteristics and detector quantum
efficiency. Typical I-V curves show excellent R0A products and strong reverse breakdown characteristics. Detector quantum efficiency was measured to be in the 60–70% range
without an antireflection coating. 相似文献
8.
M. F. Vilela K. R. Olsson E. M. Norton J. M. Peterson K. Rybnicek D. R. Rhiger C. W. Fulk J. W. Bangs D. D. Lofgreen S. M. Johnson 《Journal of Electronic Materials》2013,42(11):3231-3238
Mercury cadmium telluride (HgCdTe) grown on large-area silicon (Si) substrates allows for larger array formats and potentially reduced focal-plane array (FPA) cost compared with smaller, more expensive cadmium zinc telluride (CdZnTe) substrates. In this work, the use of HgCdTe/Si for mid- wavelength/long-wavelength infrared (M/LWIR) dual-band FPAs is evaluated for tactical applications. A number of M/LWIR dual-band HgCdTe triple-layer n-P-n heterojunction device structures were grown by molecular-beam epitaxy (MBE) on 100-mm (211)Si substrates. Wafers exhibited low macrodefect densities (< 300 cm?2). Die from these wafers were mated to dual-band readout integrated circuits to produce FPAs. The measured 81-K cutoff wavelengths were 5.1 μm for band 1 (MWIR) and 9.6 μm for band 2 (LWIR). The FPAs exhibited high pixel operability in each band with noise-equivalent differential temperature operability of 99.98% for the MWIR band and 98.7% for the LWIR band at 81 K. The results from this series are compared with M/LWIR FPAs from 2009 to address possible methods for improvement. Results obtained in this work suggest that MBE growth defects and dislocations present in devices are not the limiting factor for detector operability, with regards to infrared detection for tactical applications. 相似文献
9.
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
10.
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
11.
High-Performance LWIR MBE-Grown HgCdTe/Si Focal Plane Arrays 总被引:1,自引:0,他引:1
Richard Bornfreund Joe P. Rosbeck Yen N. Thai Edward P. Smith Daniel D. Lofgreen Mauro F. Vilela Aimee A. Buell Michael D. Newton Kenneth Kosai Scott M. Johnson Terry J. de Lyon John E. Jensen Meimei Z. Tidrow 《Journal of Electronic Materials》2007,36(8):1085-1091
We have been actively pursuing the development of long-wavelength infrared (LWIR) HgCdTe grown by molecular beam epitaxy (MBE)
on large-area silicon substrates. The current effort is focused on extending HgCdTe/Si technology to longer wavelengths and
lower temperatures. The use of Si versus bulk CdZnTe substrates is being pursued due to the inherent advantages of Si, which
include available wafer sizes (as large as 300 mm), lower cost (both for the substrates and number of die per wafer), compatibility
with semiconductor processing equipment, and the match of the coefficient of thermal expansion with silicon read-out integrated
circuit (ROIC). Raytheon has already demonstrated low-defect, high-quality MBE-grown HgCdTe/Si as large as 150 mm in diameter.
The focal plane arrays (FPAs) presented in this paper were grown on 100 mm diameter (211)Si substrates in a Riber Epineat
system. The basic device structure is an MBE-grown p-on-n heterojunction device. Growth begins with a CdTe/ZnTe buffer layer followed by the HgCdTe active device layers; the entire
growth process is performed in␣situ to maintain clean interfaces between the various layers. In this experiment the cutoff wavelengths were varied from 10.0 μm to 10.7 μm at 78 K. Detectors with >50% quantum efficiency and R
0
A ∼1000 Ohms cm2 were obtained, with 256 × 256, 30 μm focal plane arrays from these detectors demonstrating response operabilities >99%.
Work supported by the Missile Defense Agency (MDA) through CACI Technologies, Inc. subcontract no. 601-05-0088, NVESD technical
task order no. TTO-01, prime contract no. DAAB07-03-D-C214, (delivery order no. 0016) 相似文献
12.
G. Destefanis J. Baylet P. Ballet P. Castelein F. Rothan O. Gravrand J. Rothman J. P. Chamonal A. Million 《Journal of Electronic Materials》2007,36(8):1031-1044
In this paper we show the latest achievements of HgCdTe-based infrared bispectral focal plane arrays (FPAs) at LETI infrared
laboratory. We present and compare the two different pixel architectures that are studied now in our laboratory, named “NPN”
and “pseudo-planar”. With these two technologies, a wide range of system applications in dual-band detection can be covered.
Advantages of both architectures will be pointed out. We also review performances obtained with these different architectures.
The first one has been studied for several years in our laboratory, and we review results obtained on FPAs of size 256 × 256 pixels
on a 25 μm pitch, in the MWIR/MWIR (3 μm/5 μm) range. Very high noise equivalent temperature difference (NETD) operability is obtained, at 99.8% for the λc = 3 μm band and 98.7% for the λc = 5 μm band. The second one has been developed more recently, to address other applications that need temporal coherence as well
as spatial coherence. We show detailed performances measured on pseudo-planar type FPAs of size 256 × 256 pixels on a 30 μm pitch, in the MWIR/LWIR (5 μm/9 μm) range. The results are also very promising for these prototypes, with NETD as low as 15 mK for an integration time as short
as 1 ms, and good operability. The main manufacturing issues are also presented and discussed for both pixel architectures.
Challenging process steps are, firstly, molecular beam epitaxy (MBE) HgCdTe heterostructure growth, on large substrates (cadmium
zinc telluride) and heterosubstrates (germanium), and, secondly, detector array fabrication on a nonplanar surface. In particular,
trenches or hole etching steps, photolithography and hybridization are crucial to improve uniformity, number of defects and
performances. Some results of surface, structural and electrical characterizations are shown to illustrate these issues. On
the basis of these results, the short-term and long-term objectives and trends for our research and development are presented,
in terms of pixel pitch reduction, wavelengths, and dual-band FPA size. 相似文献
13.
J. Ziegler J. Wenisch R. Breiter D. Eich H. Figgemeier P. Fries H. Lutz R. Wollrab 《Journal of Electronic Materials》2014,43(8):2935-2940
In recent years, continuous progress has been published in the development of HgCdTe (MCT) infrared (IR) focal plane arrays (FPAs) fabricated by molecular beam epitaxy on GaAs substrates. In this publication, further characterization of the state-of-the art 1280 × 1024 pixel, 15-μm pitch detector fabricated from this material in both the mid-wavelength (MWIR) and long-wavelength (LWIR) IR region will be presented. For MWIR FPAs, the percentage of defective pixel remains below 0.5% up to an operating temperature (T OP) of around 100 K. For the LWIR FPA, an operability of 99.25% was achieved for a T OP of 76 K. Additionally, the beneficial effect of the inclusion of MCT layers with a graded composition region was investigated and demonstrated on current–voltage (IV) characteristics on test diodes in a MWIR FPA. 相似文献
14.
F. Aqariden P.D. Dreiske M.A. Kinch P.K. Liao T. Murphy H.F. Schaake T.A. Shafer H.D. Shih T.H. Teherani 《Journal of Electronic Materials》2007,36(8):900-904
Hg1−x
Cd
x
Te samples of x ~ 0.3 (in the midwave infrared, or MWIR, spectral band) were prepared by molecular beam epitaxy (MBE) for fabrication into
30-μm-pitch, 256 × 256, front-side-illuminated, high-density vertically-integrated photodiode (HDVIP) focal plane arrays (FPAs).
These MBE Hg1−x
Cd
x
Te samples were grown on CdZnTe(211) substrates prepared in this laboratory; they were ~10-μm thick and were doped with indium to ~5 × 1014 cm−3. Standard HDVIP process flow was employed for array fabrication. Excellent array performance data were obtained from these
MWIR arrays with MBE HgCdTe material. The noise-equivalent differential flux (NEΔΦ) operability of the best array is 99.76%,
comparable to the best array obtained from liquid-phase epitaxy (LPE) material prepared in this laboratory. 相似文献
15.
M. Carmody J. G. Pasko D. Edwall M. Daraselia L. A. Almeida J. Molstad J. H. Dinan J. K. Markunas Y. Chen G. Brill N. K. Dhar 《Journal of Electronic Materials》2004,33(6):531-537
In the past several years, we have made significant progress in the growth of CdTe buffer layers on Si wafers using molecular
beam epitaxy (MBE) as well as the growth of HgCdTe onto this substrate as an alternative to the growth of HgCdTe on bulk CdZnTe
wafers. These developments have focused primarily on mid-wavelength infrared (MWIR) HgCdTe and have led to successful demonstrations
of high-performance 1024×1024 focal plane arrays (FPAs) using Rockwell Scientific’s double-layer planar heterostructure (DLPH)
architecture. We are currently attempting to extend the HgCdTe-on-Si technology to the long wavelength infrared (LWIR) and
very long wavelength infrared (VLWIR) regimes. This is made difficult because the large lattice-parameter mismatch between
Si and CdTe/HgCdTe results in a high density of threading dislocations (typically, >5E6 cm−2), and these dislocations act as conductive pathways for tunneling currents that reduce the RoA and increase the dark current of the diodes. To assess the current state of the LWIR art, we fabricated a set of test diodes
from LWIR HgCdTe grown on Si. Silicon wafers with either CdTe or CdSeTe buffer layers were used. Test results at both 78 K
and 40 K are presented and discussed in terms of threading dislocation density. Diode characteristics are compared with LWIR
HgCdTe grown on bulk CdZnTe. 相似文献
16.
Ashok K. Sood James E. Egerton Yash R. Puri Enrico Bellotti Donald D’Orsogna Latika Becker Raymond Balcerak Ken Freyvogel Robert Richwine 《Journal of Electronic Materials》2005,34(6):909-912
Multicolor infrared (IR) focal planes are required for high-performance sensor applications. These sensors will require multicolor
focal plane arrays (FPAs) that will cover various wavelengths of interest in mid wavelength infrared/long wavelength infrared
(MWIR/LWIR) and long wavelength infrared/very long wavelength infrared (LWIR/VLWIR) bands. There has been significant progress
in HgCdTe detector technology for multicolor MWIR/LWIR and LWIR/VLWIR FPAs.1–3 Two-color IR FPAs eliminate the complexity of multiple single-color IR FPAs and provide a significant reduction of weight
and power in simpler, reliable, and affordable systems. The complexity of a multicolor IR detector MWIR/LWIR makes the device
optimization by trial and error not only impractical but also merely impossible. Too many different geometrical and physical
variables need to be considered at the same time. Additionally, material characteristics are only relatively controllable
and depend on the process repeatability. In this context, the ability of performing “simulation experiments” where only one
or a few parameters are carefully controlled is paramount for a quantum improvement of a new generation of multicolor detectors
for various applications. 相似文献
17.
E. P. G. Smith E. A. Patten P. M. Goetz G. M. Venzor J. A. Roth B. Z. Nosho J. D. Benson A. J. Stoltz J. B. Varesi J. E. Jensen S. M. Johnson W. A. Radford 《Journal of Electronic Materials》2006,35(6):1145-1152
High-performance 20-μm unit-cell two-color detectors using an n-p+-n HgCdTe triple-layer heterojunction (TLHJ) device architecture grown by molecular beam epitaxy (MBE) on (211)-oriented CdZnTe
substrates with midwavelength (MW) infrared and long wavelength (LW) infrared spectral bands have been demonstrated. Detectors
with nominal MW and LW cut-off wavelengths of 5.5 μm and 10.5 μm, respectively, exhibit 78 K LW performance with >70 % quantum
efficiency, reverse bias dark currents below 300 pA, and RA products (zero field of view, 150-mV bias) in excess of 1×103 Ωcm2. Temperature-dependent current-voltage (I–V) detector measurements show diffusion-limited LW dark current performance extending
to temperatures below 70 K with good operating bias stability (150 mV ± 50 mV). These results reflect the successful implementation
of MBE-grown TLHJ detector designs and the introduction of advanced photolithography techniques with inductively coupled plasma
(ICP) etching to achieve high aspect ratio mesa delineation of individual detector elements with benefits to detector performance.
These detector improvements complement the development of high operability large format 640×480 and 1280×720 two-color HgCdTe
infrared focal plane arrays (FPAs) to support third generation forward looking infrared (FLIR) systems. 相似文献
18.
M. Reddy J. M. Peterson S. M. Johnson T. Vang J. A. Franklin E. A. Patten W. A. Radford J. W. Bangs D. D. Lofgreen 《Journal of Electronic Materials》2009,38(8):1764-1770
This paper presents the progress in the molecular beam epitaxy (MBE) growth of HgCdTe on large-area Si and CdZnTe substrates
at Raytheon Vision Systems. We report a very high-quality HgCdTe growth, for the first time, on an 8 cm × 8 cm CdZnTe substrate.
This paper also describes the excellent HgCdTe growth repeatability on multiple 7 cm × 7 cm CdZnTe substrates. In order to
study the percentage wafer area yield and its consistency from run to run, small lots of dual-band long-wave infrared/long-wave
infrared triple-layer heterojunction (TLHJ) layers on 5 cm × 5 cm CdZnTe substrates and single-color double-layer heterojunction
(DLHJ) layers on 6-inch Si substrates were grown and tested for cutoff wavelength uniformity and micro- and macrovoid defect
density and uniformity. The results show that the entire lot of 12 DLHJ-HgCdTe layers on 6-inch Si wafers meet the testing
criterion of cutoff wavelength within the range 4.76 ± 0.1 μm at 130 K and micro- and macrovoid defect density of ≤50 cm−2 and 5 cm−2, respectively. Likewise, five out of six dual-band TLHJ-HgCdTe layers on 5 cm × 5 cm CdZnTe substrates meet the testing criterion
of cutoff wavelength within the range 6.3 ± 0.1 μm at 300 K and micro- and macrovoid defect density of ≤2000 cm−2 and 500 cm−2, respectively, on the entire wafer area. Overall we have found that scaling our HgCdTe MBE process to a 10-inch MBE system
has provided significant benefits in terms of both wafer uniformity and quality. 相似文献
19.
M. Reddy J.M. Peterson D.D. Lofgreen J.A. Franklin T. Vang E.P.G. Smith J.G.A. Wehner I. Kasai J.W. Bangs S.M. Johnson 《Journal of Electronic Materials》2008,37(9):1274-1282
Molecular beam epitaxy (MBE) growth of HgCdTe on large-size Si (211) and CdZnTe (211)B substrates is critical to meet the
demands of extremely uniform and highly functional third-generation infrared (IR) focal-panel arrays (FPAs). We have described
here the importance of wafer maps of HgCdTe thickness, composition, and the macrodefects across the wafer not only to qualify
material properties against design specifications but also to diagnose and classify the MBE-growth-related issues on large-area
wafers. The paper presents HgCdTe growth with exceptionally uniform composition and thickness and record low macrodefect density
on large Si wafers up to 6-in in diameter for the detection of short-wave (SW), mid-wave (MW), and long-wave (LW) IR radiation.
We have also proposed a cost-effective approach to use the growth of HgCdTe on low-cost Si substrates to isolate the growth-
and substrate-related problems that one occasionally comes across with the CdZnTe substrates and tune the growth parameters
such as growth rate, cutoff wavelength (λ
cutoff) and doping parameters before proceeding with the growth on costly large-area CdZnTe substrates. In this way, we demonstrated
HgCdTe growth on large CdZnTe substrates of size 7 cm × 7 cm with excellent uniformity and low macrodefect density.
Received December 7, 2007; accepted February 25, 2008 相似文献
20.
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