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Article
Defects and the Formation of Impurity ‘Hot Spots’ in HgCdTe/CdZnTe
The formation of impurity ‘hot spot’ macro-defects—localized high impurity level contaminates—is examined. The evolution of macro-defects through their critical stages: as-received CdZnTe substrate, molecular ...
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Article
Impurity ‘Hot Spots’ in MBE HgCdTe/CdZnTe
In this work, impurity ‘hot spot’ macro-defects—high impurity level macro-defect contaminates were examined. ‘Hot spots’ have very high localized concentrations of: K, Mg, Ni, Cr, Mn, Ca, Al, Na, Fe, and Cu. F...
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Article
Impact of CdZnTe Substrates on MBE HgCdTe Deposition
The highest sensitivity, lowest dark current infrared focal plane arrays (IRFPAs) are produced using HgCdTe on CdZnTe substrates. As-received state-of-the-art CdZnTe 6 × 6 and 7 × 7.5 cm substrates were analyz...
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Article
Analysis of Etched CdZnTe Substrates
State-of-the-art as-received (112)B CdZnTe substrates have been examined for surface impurity contamination and polishing residue. Two 4 cm × 4 cm and one 6 cm × 6 cm (112)B state-of-the-art as-received CdZnTe...
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Article
As-Received CdZnTe Substrate Contamination
State-of-the-art as-received (112)B CdZnTe substrates were examined for surface impurity contamination, polishing damage, and tellurium precipitates/inclusions. A maximum surface impurity concentration of Al =...
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Article
Impact of Tellurium Precipitates in CdZnTe Substrates on MBE HgCdTe Deposition
State-of-the-art (112)B CdZnTe substrates were examined for near-surface tellurium precipitate-related defects. The Te precipitate density was observed to be fairly uniform throughout the bulk of the wafer, in...
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Article
Impurity Gettering in (112)B HgCdTe/CdTe/Alternate Substrates
The crystalline structure and impurity profiles of HgCdTe/CdTe/alternate substrate (AS; Si and GaAs are possibilities) and CdTe/AS were analyzed by secondary-ion mass spectrometry, atomic force microscopy, etc...
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Article
Growth and Analysis of HgCdTe on Alternate Substrates
Dislocations generated at the HgCdTe/CdTe(buffer layer) interface are demonstrated to play a significant role in influencing the crystalline characteristics of HgCdTe epilayers on alternate substrates (AS). A ...
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Article
Microstructural Characterization of CdTe(211)B/ZnTe/Si(211) Heterostructures Grown by Molecular Beam Epitaxy
Transmission electron microscopy and small-probe microanalysis have been used to investigate the microstructure and compositional profiles of CdTe(211)B/ZnTe/Si(211) heterostructures. Thin ZnTe buffer layers a...
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Article
Dislocation Analysis in (112)B HgCdTe/CdTe/Si
High-quality (112)B HgCdTe/Si epitaxial films with a dislocation density of ∼9 × 105 cm−2 as determined by etch pit density (EPD) measurements have been obtained by thermal cyclic annealing (TCA). The reduction o...
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Article
The Distribution Tail of LWIR HgCdTe-on-Si FPAs: a Hypothetical Physical Mechanism
A model is proposed to explain disparities found in the operability values and histograms for long-wavelength infrared HgCdTe focal-plane arrays fabricated on Si substrates compared with those fabricated on Cd...
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Article
Evaluation of Surface Cleaning of Si(211) for Molecular-Beam Epitaxy Deposition of Infrared Detectors
We report an assessment of the reproducibility of the HF cleaning process and As passivation prior to the nucleation of ZnTe on the Si(211) surface using temperature desorption spectroscopy, ion scattering spe...
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Article
Characterization of Dislocations in (112)B HgCdTe/CdTe/Si
The electrical performance of HgCdTe/Si photodiodes is shown not to have a direct relationship with the dislocation density as revealed by defect etching. This has led to an equivalent circuit model to explain...
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Article
Wafer Map** Using Deuterium Enhanced Defect Characterization
Deuterium (as well as other hydrogen isotopes) binds with a wide range of morphological defects in semiconductors and, as such, becomes distributed similarly to those defects. Thus, the deuterium profile withi...
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Article
Topography and Dislocations in (112)B HgCdTe/CdTe/Si
Scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray diffraction (XRD) measurements all indicate an approximate factor of ten increase in the Everson etch pit density (EPD) over standar...
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Article
Dark current generating mechanisms in short wavelength infrared photovoltaic detectors
The current-voltage characteristics and quantum efficiencies of double layer planar heterostructure photodiodes were investigated. Results are reported on devices with cutoff wavelengths of 1.8, 2.4, and 3.3 µ...
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Article
VSWIR to VLWIR MBE grown HgCdTe material and detectors for remote sensing applications
The molecular beam epitaxy (MBE) growth technology is inherently flexible in its ability to change the Hg1−xCdxTe material’s bandgap within a growth run and from growth run to growth run. This bandgap engineering...
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Article
High performance SWIR HgCdTe detector arrays
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/Cd...
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Article
Characteristics and uniformity of group V implanted and annealed HgCdTe heterostructure
This work presents characterization of implanted and annealed double layer planar heterostructure HgCdTe for p-on-n photovoltaic devices. Our observation is that compositional redistribution in the structure d...
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Article
Uniform low defect density molecular beam epitaxial HgCdTe
This paper describes recent advances in MBE HgCdTe technology. A new 3 inch production molecular beam epitaxy (MBE) system, Riber Model 32P, was installed at Rockwell in 1994. The growth technology developed o...
