-
Article
In Situ Band-Edge Monitoring of Cd1−yZnyTe Substrates for Molecular Beam Epitaxy of HgCdTe
We demonstrate the benefits of in situ band-edge monitoring of CdZnTe substrates for molecular beam epitaxy (MBE). The production of large-area Cd1−yZnyTe(211)B substrates up to and exceeding 8 × 8 cm2 brings new...
-
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 ...
-
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...
-
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...
-
Article
Correlation of Etch Pits and Dislocations in As-grown and Thermal Cycle-Annealed HgCdTe(211) Films
This paper reports observations of the different types of etch pits and dislocations present in thick HgCdTe (211) layers grown by molecular beam epitaxy on CdTe/Si (211) composite substrates. Dislocation anal...
-
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...
-
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 =...
-
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...
-
Article
A Review of the Characterization Techniques for the Analysis of Etch Processed Surfaces of HgCdTe and Related Compounds
HgCdTe is the material system of choice for many infrared sensing applications. Growth of this material can often be challenging. However, processing of this material system can be equally as challenging. Inco...
-
Article
Analysis of Mesa Dislocation Gettering in HgCdTe/CdTe/Si(211) by Scanning Transmission Electron Microscopy
Due to its strong infrared absorption and variable band-gap, HgCdTe is the ideal detector material for high-performance infrared focal-plane arrays (IRFPAs). Next-generation IRFPAs will utilize dual-color high...
-
Article
Comparison of the Schaake and Benson Etches to Delineate Dislocations in HgCdTe Layers
The morphology and classification of etch pits in molecular beam epitaxy-grown (211) HgCdTe/CdTe/Si layers were investigated using the Schaake and Benson etch pit density (EPD) etches. The two EPD etches were ...
-
Article
The Surface Kinetics of MBE-Grown CdTe (211)B During In Situ Cyclic Annealing
The surface kinetics of CdTe (211)B grown by molecular beam epitaxy (MBE) is investigated using spectroscopic ellipsometry (SE) during in situ cyclic annealing. A method of measuring sublimation rates from high-i...
-
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...
-
Article
Cross-Sectional Study of Macrodefects in MBE Dual-Band HgCdTe on CdZnTe
HgCdTe dual-band mid-wave infrared/long-wave infrared focal-plane arrays on CdZnTe are a key component in advanced electrooptic sensor applications. Molecular beam epitaxy (MBE) has been used successfully for ...
-
Article
Reduction of Dislocation Density by Producing Novel Structures
HgCdTe, because of its narrow band gap and low dark current, is the infrared detector material of choice for several military and commercial applications. CdZnTe is the substrate of choice for HgCdTe as it can...
-
Article
Understanding the Evolution of CdTe Buffer Layer Surfaces on ZnTe/Si(211) and GaAs(211)B During Cyclic Annealing
We present the results of a detailed study of the changes that occur on CdTe buffer layer surfaces grown on ZnTe/Si(211) and GaAs(211)B during the routine thermal cyclic annealing (TCA) process. Observations i...
-
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 ...
-
Article
High-Sensitivity Visible-Blind AlGaN Photodiodes and Photodiode Arrays
Visible-blind UV cameras based on a 32 × 32 array of backside-illuminated GaN/AlGaN p-i-n photodiodes have been successfully demonstrated. The photodiode arrays were hybridized to silicon readout integrated ci...
-
Article
Reduction of Dislocation Density in HgCdTe on Si by Producing Highly Reticulated Structures
HgCdTe, because of its narrow band gap and low dark current, is the infrared detector material of choice for several military and commercial applications. CdZnTe is the substrate of choice for HgCdTe as it can...
-
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...
