The observation of defects on (100) CdTe surfaces by chemical etching

1992 ◽  
Vol 50 (2) ◽  
pp. 1424-1425
Author(s):  
M.E. Lee
Keyword(s):  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Chemical Etching ◽  
Crystalline Perfection ◽  
Crystalline Defects ◽  
High Incidence ◽  
Crystallographic Defects ◽  
Cdznte Substrates ◽  
Device Technology

The crystalline perfection of bulk CdTe substrates plays an important role in their use in infrared device technology. The application of chemical etchants to determine crystal polarity or the density and distribution of crystallographic defects in (100) CdTe is not well understood. The lack of data on (100) CdTe surfaces is a result of the apparent difficulty in growing (100) CdTe single crystal substrates which is caused by a high incidence of twinning. Many etchants have been reported to predict polarity on one or both (111) CdTe planes but are considered to be unsuitable as defect etchants. An etchant reported recently has been considered to be a true defect etchant for CdTe, MCT and CdZnTe substrates. This etchant has been reported to reveal crystalline defects such as dislocations, grain boundaries and inclusions in (110) and (111) CdTe. In this study the effect of this new etchant on (100) CdTe surfaces is investigated.The single crystals used in this study were (100) CdTe as-cut slices (1mm thickness) from Bridgman-grown ingots.

The Application of an Automated Single Crystal Orienter for Large Specimens

1980 ◽  
Vol 24 ◽  
pp. 283-287
Author(s):  
A. V. Karg ◽  
J. M. Walsh ◽  
J. M. LaGrotta
Keyword(s):  
Single Crystal ◽  
Grain Boundaries ◽  
Stereographic Projection ◽  
Crystal Quality ◽  
Crystallographic Defects

AbstractA special purpose, automated, four circle goniometer arrangement has been developed for the rapid orientation of large specimens of single crystal turbine hardware. This system rapidly establishes the complete orientation of these large components and generates a fully documented stereographic projection. The system is also capable of generating detailed information on crystal quality including rocking curves in several dimensions. X, Y translational capability of the specimen makes it possible to characterize crystallographic defects such as sub-grain boundaries.

scholarly journals Crystal growth of Ru-doped congruent LiNbO3and investigation of crystalline perfection and optical properties

2015 ◽  
Vol 48 (6) ◽  
pp. 1753-1760 ◽  
Author(s):  
B. Riscob ◽  
Indranil Bhaumik ◽  
S. Ganesamoorthy ◽  
R. Bhatt ◽  
N. Vijayan ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Gap Analysis ◽  
Czochralski Method ◽  
Growth Direction ◽  
Crystalline Perfection ◽  
Diffraction Curve ◽  
Radial Gradient ◽  
Prism Coupler ◽  
Optical Sign

Single crystals of undoped and Ru-doped congruent LiNbO3(LN) were successfully grown by the Czochralski method. The axial and radial gradient of the radio frequency furnace was controlled in order to obtain crack-free single crystals. Wafers were cut from the grown Ru-doped single crystal at different axial positions along the growth direction and subjected to various characterization analyses. Good optical homogeneity and low residual strain in the grown crystal is confirmed by the conoscopy patterns. Further, it is confirmed that Ru doping does not influence the optical sign of the crystal. From a high-resolution X-ray diffractometry analysis, it is evident that the as-grown undoped LN crystal exhibited better crystalline perfection with a single and sharp diffraction curve in comparison to the Ru-doped crystals, which are characterized by a broader diffraction curve. Absorption coefficient and band-gap analysis across the axial length revealed a concentration variation of Ru across the length. Refractive index measurements carried out using a prism coupler showed variation in the optical birefringence, also due to the variation of Ru concentration at different positions of the grown single crystal.

THE EFFECTS OF GRAIN BOUNDARIES ON THE PLASTIC DEFORMATION OF ZINC CRYSTALS

1957 ◽  
Vol 35 (1) ◽  
pp. 38-47 ◽  
Author(s):  
G. B. Craig ◽  
B. Chalmers
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Basal Plane ◽  
Basal Slip ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

The tensile plastic deformation of single-crystal and tricrystal specimens of zinc was investigated by analysis of the external change in shape of the specimens, and of the changes in X-ray diffraction patterns. It was demonstrated that the single crystals deformed by slip on the basal plane, but pyramidal as well as basal slip occurred in specimens containing grain boundaries.

Relaxor Single-Crystal Plates with Nano-Size Ferroelectric Domains Applying to Ultrasonic Prove for Medical Uses

2016 ◽  
Vol 102 ◽  
pp. 57-64
Author(s):  
Toshio Ogawa ◽  
Taiki Ikegaya
Keyword(s):  
Bulk Modulus ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Domain Alignment

Sound velocities were measured in relaxor single-crystal plates, included in piezoelectric transducers for medical uses, using an ultrasonic precision thickness gauge with high-frequency pulse generation. The velocities were compared with the ones of piezoelectric ceramics in order to clarify characteristics of the single crystals. Estimating the difference in the sound velocities and elastic constants in the single crystals and ceramics, it was possible to evaluate effects of domain and grain boundaries on elastic constants. Existence of domain boundaries in single crystal affected the decrease in Young’s modulus, rigidity, Poisson’s ratio and bulk modulus. While existence of grain boundaries affected the decrease in Young’s modulus and rigidity, Poisson’s ratio and bulk modulus increased. It was thought these phinomina come from domain alignment by DC poling, and both the boundaries act as to absorb mechanical stress by defects due to the boundaries. In addition, the origin of piezoelectricity in single crystals is caused by low bulk modulus and Poisson’s ratio, and high Young’s modulus and rigidity in comparison with ceramics. On the contrary, the origin of piezoelectricity in ceramics is caused by high Poisson’s ratio by high bulk modulus, and furthermore, low Young’s modulus and rigidity due to domain alignment.

scholarly journals PRODUCTION OF HYIGH-PURITY ZINC SINGLE CRYSTALS BY VERTICAL DIRECTED CRYSTALLIZATION METHOD

2020 ◽  
pp. 17-20
Author(s):  
A.P. Shcherban ◽  
G.P. Kovtun ◽  
D.A. Solopikhin ◽  
Yu.V. Gorbenko ◽  
T.Yu. Rudycheva ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
High Purity ◽  
Growth Direction ◽  
Directed Crystallization ◽  
Micro Structure ◽  
Crystalline Perfection ◽  
Impurity Composition ◽  
Crystallization Method

A seedless process has been developed to produce high-purity Zn single crystals by the method of vertical di-rected crystallization from a melt. The output of a single crystal structure is from 60 to 80%. Crystals with different growth directions were obtained: [1015] and [0002]. The deviation angles of the growth direction plane relative to the normal to the axis of the sample are 0.5...6°. Microhardness, crystalline perfection of single crystals and micro-structure have been determined. The impurity composition of the start and end parts of single crystals produced from initial grades of zinc of various purities was studied. The developed process can be used to grow single crystals low-melting metals, such as Cd, Pb, Te, In, Bi, Sn, etc.

The Chemical Etch of Tungsten Single Crystals and Foils With XeF2

1986 ◽  
Vol 68 ◽  
Author(s):  
A. Bensaoula ◽  
J. Stozier ◽  
A. Ignatiev ◽  
J. Wolfe
Keyword(s):  
Kinetic Model ◽  
Single Crystal ◽  
Single Crystals ◽  
Chemical Etching ◽  
Molecular Beam ◽  
Ion Current ◽  
Fluorine Concentration ◽  
Product Yields ◽  
Chemical Etch ◽  
Current Densities

AbstractThe chemical etching of W(100) single crystals and polycrystalline tungsten foils using a XeF2 molecular beam has been studied with and without simultaneous bombardment by energetic inert ions.The surface fluorine concentration, measured under different XeF2 pressures (10−7 to 10−5 torr) and ion current densities, is found to be always less than a monolayer.Depth profiles of the fluorine layer show that in both single crystal and poly samples, the fluorine is surface localized, although slightly deeper in the W(100).A kinetic model is presented to account for the enhanced etching under ion bombardment.The mechanism proposed is mainly a defect driven enhancement of the etch yield.This model is consistent with both the fluorine concentrations measured in this work as well as the etch product yields reported by Winters.

Impedanzmessungen an Tetraiodomercuraten/Impedance Spectroscopy of Tetraiodomercurates

1992 ◽  
Vol 47 (1) ◽  
pp. 17-21 ◽  
Author(s):  
K. Brodersen ◽  
H. Göhr ◽  
J. Schrenk
Keyword(s):  
Phase Transitions ◽  
Impedance Spectroscopy ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Double Layer ◽  
Powder Sample ◽  
Ionic Mobilities

As thermochromic compounds, tetraiodomercurates show phase transitions, which have been investigated by impedance spectroscopy. In the case of Ag2HgI4 and Cu2HgI4 we found clear changes of conductivity not present with HgI2. In all cases the main resistance is caused by the grain boundaries between the single crystals of the powder sample. Also diffusion in the double layer in front of the surface of the electrodes influences the spectra. Single crystal measurements of Hgl, show the different ionic mobilities along the various crystallographic directions.

scholarly journals Enhancement of SHG efficiency by urea doping in ZTS single crystals and its correlation with crystalline perfection as revealed by Kurtz powder and high-resolution X-ray diffraction methods

2010 ◽  
Vol 43 (1) ◽  
pp. 154-162 ◽  
Author(s):  
G. Bhagavannarayana ◽  
S. K. Kushwaha
Keyword(s):  
High Resolution ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Second Harmonic ◽  
Critical Concentration ◽  
Solution Technique ◽  
Infrared Spectrometry ◽  
Crystalline Perfection ◽  
X Ray ◽  
Shg Efficiency

The enhancement of second-harmonic generation (SHG) efficiency by urea doping in tristhioureazinc(II) sulfate (ZTS) single crystals and its correlation with crystalline perfection have been investigated. ZTS is a potential semiorganic nonlinear optical material. Pure and urea-doped single crystals of ZTS have been successfully grown by the slow evaporation solution technique. The presence of dopant has been confirmed and analysed by Fourier transform infrared spectrometry. The influence of urea doping at different concentrations on crystalline perfection has been thoroughly assessed by high-resolution X-ray diffractometry (HRXRD). HRXRD studies revealed that the ZTS crystals could accommodate urea up to a critical concentration without any deterioration in crystalline perfection. Above this concentration, very low angle structural grain boundaries developed and it seems the excess urea above the critical concentration was segregated along the grain boundaries. At very high doping concentrations, the crystals were found to contain mosaic blocks. The SHG efficiency has been studied using the Kurtz powder technique. The relative SHG efficiency of the crystals was found to increase substantially with the increase in urea concentration. The correlation found between crystalline perfection and SHG efficiency is discussed.

Mounting an individual submicrometer sized single crystal

1996 ◽  
Vol 211 (6) ◽  
Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
High Vacuum ◽  
Nanometer Resolution ◽  
Micro Manipulator ◽  
Scanning Electron

AbstractWe developed a new micro manipulator for mounting individual sub-micrometer sized single crystals within a scanning electron microscope. The translations are realized via a commercially available piezomicroscope, adapted for high vacuum usage and realize nanometer resolution. With this novel instrument it is routinely possible to mount individual single crystals with sizes down to 0.1

Decapsulation Techniques for Cu Wire Bonding Package

2009 ◽  
Author(s):  
Dongmei Meng ◽  
Joe Rupley ◽  
Chris McMahon
Keyword(s):  
Laser Ablation ◽  
Thin Layer ◽  
Chemical Etching ◽  
Wire Bonding ◽  
Methods And Techniques ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Reliability Issue ◽  
Etch Time ◽  
Device Technology

Abstract This paper presents decapsulation solutions for devices bonded with Cu wire. By removing mold compound to a thin layer using a laser ablation tool, Cu wire bonded packages are decapsulated using wet chemical etching by controlling the etch time and temperature. Further, the paper investigates the possibilities of decapsulating Cu wire bonded devices using full wet chemical etches without the facilitation of laser ablation removing much of mold compound. Additional discussion on reliability concerns when evaluating Cu wirebond devices is addressed here. The lack of understanding of the reliability of Cu wire bonded packages creates a challenge to the FA engineer as they must develop techniques to help understanding the reliability issue associated with Cu wire bonding devices. More research and analysis are ongoing to develop appropriate analysis methods and techniques to support the Cu wire bonding device technology in the lab.

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