Growth of Large-Diameter CdZnTe and CdTeSe Boules for Hg1−xCdxTe Epitaxy: Status and Prospects

1989 ◽  
Vol 161 ◽  
Author(s):  
S. Sen ◽  
S.M. Johnson ◽  
J.A. Kiele ◽  
W.H. Konkel ◽  
J.E. Stannard
Keyword(s):  
Single Crystal ◽  
Defect Density ◽  
Large Diameter ◽  
Cylindrical Body ◽  
Growth Conditions ◽  
Grain Structure ◽  
Current Status ◽  
Conductive Heat ◽  
Large Area ◽  
Ir Detector

ABSTRACTSingle crystals of CdTe or dilute alloys of Cd1−yZnyTe (y ≤ 0.04) and CdTe1−zSez (z ≤ 0.04) with low defect density and large single-crystal area (>30 cm2) are required as substrates for high-quality epitaxial Hg1−xCdxTe thin films in the infrared (IR) detector industry. Bridgman or gradient freeze has been the most common current technique used for growing these materials. This paper reviews the current status and the evolution at SBRC of one variation of the Bridgman technique, viz., vertical-modified Bridgman (VMB), for producing large-area substrates with excellent uniformity and reproducibility. CdTe, Cd1−yZnyTe (y ≤ 0.04) and CdTe1−zSez (z ≤ 0.04) boules of 5-to 7.5-cm diameter have been grown unseeded in the present version of the VMB growth system. In general, under optimum growth conditions, the boules have the smallest grain structure (several grains) at the tip end with enhancement of grain selection as the cylindrical body of the boule is approached, resulting in one predominant and large grain occupying 70 to 80 percent of the entire boule volume; {111}-oriented Cd1−yZnyTe and CdTe1−zSez substrates with single-crystal areas as large as 50 to 60 cm2 have been obtained from these boules. Crystal quality characterized by x-ray rocking curve, IR transmission (2.5 to 20 µm), low-temperature photoluminescence, and Hall-effect measurements as a function of temperature, showed a strong correlation with the starting material quality (especially that of elemental Te and Se). Analyses of the thermal history during growth reveals that the presence of the ampoule (with charge) increases the temperature inside the furnace by 10 to 15 degrees. The temperature gradient at the tip was measured to be 8 to 10°C/cm and it dropped to 4 to 5°C/cm beyond 2.5 cm from the tip - where rapid enhancement of grain selection takes place in most boules. The effect of this temperature rise on the initial crystallization near the tip of a boule can be explained from the numerical thermal model that was developed for the growth process with radiative and conductive heat transfer included and using a temperature profile similar to that existing in the actual growth furnace. Conditions for maximizing the fraction solidifying with a slightly convex interface, hence maximizing the single-crystal yield are discussed.

Improved Quality of Bulk II-VI Substrates for HgcdTe and HgZnTe Epitaxy

1994 ◽  
Vol 299 ◽  
Author(s):  
Sanghamitra Sen ◽  
John E. Stannard
Keyword(s):  
Defect Density ◽  
Substrate Material ◽  
Current Status ◽  
Large Area ◽  
Ir Detector ◽  
Lattice Matching ◽  
Research Areas ◽  
Critical Issues ◽  
Common Technique ◽  
Primary Focus

AbstractSingle crystals of CdTe or dilute alloys of Cd1−yZnyTe (y≤0.04) and CdTe1−zSez (z ≤0.04) with low defect density, high purity and large single-crystal area (>30 cm2) are required as substrates for high-quality epitaxial Hg1−xCdxTe thin films in the infrared (IR) detector industry. Bridgman or gradient freeze is the most common technique used for commercial production of these materials because of its success in producing large area substrates of good quality and reproducibility. For epitaxial growth of Hg1−xZnxTe, which has been of considerable interest in recent years as an IR detector material, the substrate of choice has been Cd0.80Zn0.20Te, for lattice matching with long wavelength Hg1−xZnxTe epitaxial layers (x = 0.13–0.14). The primary focus of this paper is on CdZnTe which is currently the preferred substrate material and most widely used for both HgCdTe and HgZnTe epitaxy. This paper reviews the current status of bulk substrate technology for IR detector applications, highlighting critical issues and essential research areas for further improvement of these materials.

Improved Quality of Bulk II-VI Substrates for HgCdTe and HgZnTe Epitaxy

1993 ◽  
Vol 302 ◽  
Author(s):  
Sanghamitra Sen ◽  
John E. Stannard
Keyword(s):  
Defect Density ◽  
Substrate Material ◽  
Current Status ◽  
Large Area ◽  
Ir Detector ◽  
Lattice Matching ◽  
Research Areas ◽  
Critical Issues ◽  
Common Technique ◽  
Primary Focus

ABSTRACTSingle crystals of CdTe or dilute alloys of Cdl−y ZnyTe (y ≤ 0.04) and CdTel−zSez (z ≤ 0.04) with low defect density, high purity and large single-crystal area (>30 cm2) are required as substrates for high-quality epitaxial Hgl−xCdxTe thin films in the infrared (IR) detector industry. Bridgman or gradient freeze is the most common technique used for commercial production of these materials because of its success in producing large area substrates of good quality and reproducibility. For epitaxial growth of Hg1−xZnxTe, which has been of considerable interest in recent years as an IR detector material, the substrate of choice has been Cd0.80Zn0.20Te, for lattice matching with long wavelength Hg1−xZnxTe epitaxial layers (x = 0.13–0.14). The primary focus of this paper is on CdZnTe which is currently the preferred substrate material and most widely used for both HgCdTe and HgZnTe epitaxy. This paper reviews the current status of bulk substrate technology for IR detector applications, highlighting critical issues and essential research areas for further improvement of these materials.

Synchrotron white beam x-ray topography (SWBXT) and high resolution triple axis diffraction studies on AlN layers grown on 4H- and 6H-SiC seeds

2004 ◽  
Vol 831 ◽  
Author(s):  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Rafael Dalmau ◽  
Raoul Schlesser ◽  
Zlatko Sitar
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Large Diameter ◽  
Laser Diodes ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
White Beam ◽  
Strain Data ◽  
Growth Experiments

ABSTRACTFor nitride based devices such as LEDs, high power FETs and laser diodes, single crystal substrates of AlN are highly desirable. While the sublimation technique is suitable for growing bulk AlN crystals, appropriate seeds are also necessary for growing large diameter oriented boules. 4H- and 6H-SiC substrates which are readily available commercially can potentially be implemented as seeds for bulk AlN growth. However, issues regarding SiC decomposition at high temperatures, thermal expansion mismatch, single crystal growth, etc. need to be addressed. Towards this end, a series of growth experiments have been carried out in a resistively heated reactor using on and off-axis 4H- and 6H-SiC substrates as seeds for AlN growth from the vapor phase. Several hundred microns thick AlN layers have been grown under different growth conditions. Synchrotron white beam x-ray topography (SWBXT) has been used to map the defect distribution in the grown layers and high resolution triple axis x-ray diffraction (HRTXD) experiments were carried out to record reciprocal space maps from which tilt, mismatch and strain data can be obtained. These results are analyzed with respect to the growth conditions in order to gain a better understanding of this growth process.

Solution Growth of 4-Inch Diameter SiC Single Crystal Using Si-Cr Based Solvent

2019 ◽  
Vol 963 ◽  
pp. 85-88 ◽  
Author(s):  
Kazuhiko Kusunoki ◽  
Yutaka Kishida ◽  
Kazuaki Seki
Keyword(s):  
Heat Transfer ◽  
Crystal Growth ◽  
Single Crystal ◽  
Large Diameter ◽  
Growth Conditions ◽  
Bulk Crystal ◽  
Solution Growth ◽  
Heat Transfer Analysis ◽  
Growth Method ◽  
The Magnetic Field

We grew large diameter and long size 4H-SiC crystals by the solution growth method using Si-Cr based solvent. To optimize the crystal growth conditions, we applied two-dimensional axisymmetric steady-state analysis to conduct a comprehensive heat transfer analysis that calculates the magnetic field, heat transfer, and liquid flow. In particular, by optimizing the solution surface temperature environment and the seed shaft structure, we suppressed parasitic undesirable crystal formations and promoted single crystal growth at the same time. Consequently, we obtained a 2-inch bulk crystal with a thickness of 20 mm and a 4-inch bulk crystal with a thickness of 15 mm.

Impurity Effects in the Growth of 4H-SiC Crystals by Physical Vapor Transport

1999 ◽  
Vol 572 ◽  
Author(s):  
V. Balakrishna ◽  
G. Augustine ◽  
R. H. Hopkins
Keyword(s):  
Electronic Device ◽  
Defect Density ◽  
Growth Parameters ◽  
Large Diameter ◽  
Growth Conditions ◽  
High Resistivity ◽  
Growth Surface ◽  
Second Phase ◽  
Impurity Effects ◽  
Growth Environment

ABSTRACTSiC is an important wide bandgap semiconductor material for high temperature and high power electronic device applications. Purity improvements in the growth environment has resulted in a two-fold benefit during growth: (a) minimized inconsistencies in the background doping resulting in high resistivity (>5000 ohm-cm) wafer yield increase from 10–15% to 70-85%, and (b) decrease in micropipe formation. Growth parameters play an important role in determining the perfection and properties of the SiC crystals, and are extremely critical in the growth of large diameter crystals. Several aspects of growth are vital in obtaining highly perfect, large diameter crystals, such as: (i) optimized furnace design, (ii) high purity growth environment, and (iii) carefully controlled growth conditions. Although significant reduction in micropipe density has been achieved by improvements in the growth process, more stringent device requirements mandate further reduction in the defect density. In-depth understanding of the mechanisms of micropipe formation is essential in order to devise approaches to eliminate them. Experiments have been performed to understand the role of growth conditions and ambient purity on crystal perfection by intentionally introducing arrays of impurity sites on one half of the growth surface. Results clearly suggest that presence of impurities or second phase inclusions during start or during growth can result in the nucleation of micropipes. Insights obtained from these studies were instrumental in the growth of ultra-low micropipe density (less than 2 micropipes cm−2 ) in 1.5 inch diameter boules.

Growth of High Quality Single Crystal ZnO Films on Sapphire by Pulsed Laser Ablation

1998 ◽  
Vol 526 ◽  
Author(s):  
A.K. Sharma ◽  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
D.E. Moxey ◽  
J.F. Muth ◽  
...  
Keyword(s):  
Single Crystal ◽  
Defect Density ◽  
Pulsed Laser ◽  
Growth Conditions ◽  
Oxygen Stoichiometry ◽  
Zno Films ◽  
High Quality ◽  
High Quality Single Crystal ◽  
Transmission Electron ◽  
Order Of Magnitude

AbstractThe structural and optical characterizations of single crystal zinc oxide films on sapphire have been performed. The ZnO films were deposited by pulsed laser deposition in an oxygen environment. These films were annealed in oxygen for further improvement in the oxygen stoichiometry. Both as-deposited and oxygen annealed films were high quality single crystal as characterized by X-ray diffraction and transmission electron microscopy. The defect density, comprised mainly of dislocations and stacking faults, was low as compared to high quality films of III-nitrides deposited on sapphire. Under these growth conditions, the ZnO films grow two dimensionally on sapphire as opposed to GaN which grows three dimensionally. The band edge photoluminescence was found to be dominant, and an order of magnitude higher in the annealed films. Transmission measurements and the electrical resistivity of the annealed films also show the films were of high quality after annealing. It is envisaged that these improvements in the quality of the ZnO films occur as a result of reduction of oxygen vacancies and the density of point defects.

Homoepitaxial Mosaic Growth and Liftoff of Diamond Films

1995 ◽  
Vol 416 ◽  
Author(s):  
Pehr E. Pehrsson ◽  
Terri Mccormick ◽  
W. Brock Alexander ◽  
Mike Marchywka ◽  
David Black ◽  
...  
Keyword(s):  
Single Crystal ◽  
Microwave Plasma ◽  
Defect Density ◽  
Diamond Films ◽  
Subsurface Damage ◽  
Diamond Lattice ◽  
Large Area ◽  
Damage Layer ◽  
Single Crystal Diamond ◽  
Homoepitaxial Layers

ABSTRACTGrowth of large area, single or almost single crystal diamond is of great importance to the electronics industry. In this work, single crystal diamonds were implanted with C+ ions, inducing a subsurface damage layer in the diamond lattice. Homoepitiaxial diamond films were then grown on the implanted crystals using a microwave plasma CVD reactor. Films grown on on-axis substrates were dominated by large numbers of hillocks, renucleation and penetration twins, while miscut substrates exhibited stepflow growth. The homoepitaxial layers were separated from the substrate by a water-based etch which selectively attacks the subsurface damage layer of the diamond lattice. The films were analyzed by Raman scattering, scanning electron microscopy (SEM), optical microscopy, photo- and cathodoluminescence, and x-ray diffraction. CVD growth on adjacent, oriented substrates formed a single, continuous diamond layer. The resulting homoepitaxial film quality, orientation, defect density and it's relationship to the underlying substrates were compared at various points on the surface, particularly the region which overgrew the gap between different substrates.

Growth Technique For Large Area Mosaic Diamond Films†

1992 ◽  
Vol 242 ◽  
Author(s):  
R. W. Pryor ◽  
M. W. Geis ◽  
H. R. Clark
Keyword(s):  
Single Crystal ◽  
Electronic Properties ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Growth Conditions ◽  
Large Area ◽  
Si Substrates ◽  
Single Crystal Diamond ◽  
The Individual

ABSTRACTA new technique has been developed to grow semiconductor grade diamond substrates with dimensions comparable to those of currently available Si wafers. Previously, the synthetic single crystal diamond that could be grown measured only a few millimeters across, compared with single crystal Si substrates which typically are 10 to 15 cm in diameter. In the technique described, an array of features is first etched in a Si substrate. The shape of the features matches that of inexpensive, synthetic faceted diamond seeds. A diamond mosaic is then formed by allowing the diamond seeds to settle out of a slurry onto the substrate, where they become fixed and oriented in the etched features. For the experiments reported, the mosaic consists of seeds ∼ 100 μm across on 100 μm centers. A mosaic film is obtained by chemical vapor deposition of homoepitaxial diamond until the individual seeds grow together. Although these films contain low angle (<1°) grain boundaries, smooth, continuous diamond films have been obtained with electronic properties substantially better than those of polycrystalline diamond films and equivalent to those of homoepitaxial single crystal diamond films. The influence of growth conditions and seeding procedures on the crystallographic and electronic properties of these mosaic diamond films is discussed.

scholarly journals Amorphous thin-film oxide power devices operating beyond bulk single-crystal silicon limit

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuki Tsuruma ◽  
Emi Kawashima ◽  
Yoshikazu Nagasaki ◽  
Takashi Sekiya ◽  
Gaku Imamura ◽  
...  
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Flexible Substrate ◽  
Single Crystal Silicon ◽  
Bulk Single Crystal ◽  
Next Generation ◽  
Power Devices ◽  
Large Area ◽  
Crystal Silicon ◽  
Amorphous Thin Film

AbstractPower devices (PD) are ubiquitous elements of the modern electronics industry that must satisfy the rigorous and diverse demands for robust power conversion systems that are essential for emerging technologies including Internet of Things (IoT), mobile electronics, and wearable devices. However, conventional PDs based on “bulk” and “single-crystal” semiconductors require high temperature (> 1000 °C) fabrication processing and a thick (typically a few tens to 100 μm) drift layer, thereby preventing their applications to compact devices, where PDs must be fabricated on a heat sensitive and flexible substrate. Here we report next-generation PDs based on “thin-films” of “amorphous” oxide semiconductors with the performance exceeding the silicon limit (a theoretical limit for a PD based on bulk single-crystal silicon). The breakthrough was achieved by the creation of an ideal Schottky interface without Fermi-level pinning at the interface, resulting in low specific on-resistance Ron,sp (< 1 × 10–4 Ω cm2) and high breakdown voltage VBD (~ 100 V). To demonstrate the unprecedented capability of the amorphous thin-film oxide power devices (ATOPs), we successfully fabricated a prototype on a flexible polyimide film, which is not compatible with the fabrication process of bulk single-crystal devices. The ATOP will play a central role in the development of next generation advanced technologies where devices require large area fabrication on flexible substrates and three-dimensional integration.

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