Structural and Photoluminescence Studies of Er Implanted Lt-GaAs:Be

1998 ◽  
Vol 510 ◽  
Author(s):  
R.L. Maltez ◽  
Z. Liliental-Weber ◽  
J. Washburn ◽  
M. Behar ◽  
P.B. Klein ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Structural Damage ◽  
Optically Active ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Total Fluence ◽  
Photoluminescence Studies ◽  
Post Implantation ◽  
Background Luminescence ◽  
Implantation Fluence

AbstractCharacteristic 1.54 μm Era3+ emission has been observed from Er-implanted and annealed, low-temperature grown GaAs:Be samples. Cross-sectional transmission electron microscopy (TEM) studies reveal very little structural damage for elevated temperature implants up to an Er total fluence of 1.36 × 1014 Er/cm2. No Er emission was observed from any of the as-implanted samples, while post-implantation annealing optimized the Er emission intensity near 650°C. The Er-emission appears on top of a broad background luminescence peaking near 1500 nm. Significant enhancement of the optically active Er incorporation was achieved when the implantation was carried out at 300TC. The Er emission intensity was found to scale linearly with the Er implantation fluence for samples with an Er concentration up to ∼1019 Er/cm3. The sample with the highest Er concentration (∼1020 Er/cm3) began to show a sublinear dependence. The beginning of Er precipitation was observed after 750°C annealing, but it could even be observed after a 650°C annealing for the highest Er concentration sample. These precipitates are likely ErAs.

Formation of Nanovoids and Nanocolumns in High Dose Hydrogen Implanted ZnO Bulk Crystals

2006 ◽  
Vol 957 ◽  
Author(s):  
Rajendra Singh ◽  
R. Scholz ◽  
U. Gösele ◽  
S. H. Christiansen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Dose ◽  
Hydrogen Ions ◽  
Bulk Crystals ◽  
Cross Sectional ◽  
Projected Range ◽  
Transmission Electron ◽  
Wafer Surfaces ◽  
Post Implantation

ABSTRACTZnO(0001) bulk crystals were implanted with 100 keV H2+ ions with various doses in the range of 5×1016 to 3×1017 cm-2. The ZnO crystals implanted up to a dose of 2.2×1017 cm-2 did not show any surface exfoliation, even after post-implantation annealing at temperatures up to 800°C for 1 h while those crystals implanted with a dose of 2.8×1017 cm-2 or higher exhibited exfoliated surfaces already in the as-implanted state. In a narrow dose window in between, controlled exfoliation could be obtained upon post-implantation annealing only. Cross-sectional transmission electron microscopy (XTEM) of the implanted ZnO samples showed that a large number of nanovoids were formed within the implantation-induced damage band. These nanovoids served as precursors for the formation of microcracks leading to the exfoliation of ZnO wafer surfaces. In addition to the nanovoids, elongated nanocolumns perpendicular to the ZnO wafer surfaces were also observed. These nanocolumns showed diameters of up to 10 nm and lengths of up to 500 nm. The nanocolumns were found in the ZnO wafer even well beyond the projected range of hydrogen ions.

Investigation of Blistering Phenomena in Hydrogen-Implanted GaN and AlN for Thin Film Layer Transfer Applications

2008 ◽  
Vol 1068 ◽  
Author(s):  
Rajendra Singh ◽  
R. Scholz ◽  
S. H. Christiansen ◽  
U. Goesele
Keyword(s):  
Thin Film ◽  
High Dose ◽  
Layer Transfer ◽  
Large Area ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Thin Film Layer ◽  
Hydrogen Implantation ◽  
Film Layer ◽  
Post Implantation

ABSTRACTHigh dose hydrogen implantation-induced blistering phenomena in GaN and AlN have been investigated for potential thin film layer transfer applications. GaN and AlN were implanted with 100 keV H2+ ions with various ion doses in the range of 5´1016 to 2.5´1017 cm−2. After implantation the samples were annealed at higher temperatures up to 800°C in order to observe the formation of surface blisters. In the case of GaN only those samples that were implanted with a dose of 1.3´1017 cm−2 or higher showed surface blistering after post-implantation annealing. For AlN the samples those were implanted with a dose of 1.0´1017 or 1.5´1017 cm−2 displayed surface blistering after post-implantation annealing. Cross-sectional transmission electron microscopy was utilized to observe the microscopic defects that eventually cause surface blistering. Large area microcracks, as revealed in the XTEM images, were clearly observed in the case of both GaN and AlN after post-implantation annealing. A comparison of the hydrogen implantation-induced blistering in GaN and AlN has also been presented.

XTEM study of phase transition in MeV ion-implanted InP

1988 ◽  
Vol 46 ◽  
pp. 796-797
Author(s):  
Fulin Xiong
Keyword(s):  
Phase Transition ◽  
Ion Implantation ◽  
Structural Changes ◽  
Ion Irradiation ◽  
Device Fabrication ◽  
Cross Sectional ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Post Implantation ◽  
Subsequent Thermal Annealing

MeV ion implantation into III-V compound semiconductors has attracted great attention in recent years because of its high potential for 3-dimensional device fabrication technology. However, a thorough understanding of associated physical processes involved is crucial before it can be universally applied. Our study on this subject with InP using cross sectional and high resolution transmission electron microscopy (XTEM, HRTEM) reveals clearly the structural changes occurring during MeV-ion-implantation and subsequent thermal annealing. It has lead to a better understanding of the mechanism of phase transition in InP under MeV ion irradiation.Samples of n-type InP(lOO) single crystalline wafers were implanted with 5 MeV-N-ions in room temperature with doses ranging from 1014 to 1016/cm2. Post-implantation annealing was carried out in a graphite strip heater at 500 C with ambient H2 flow.Fig. 1 shows a typical XTEM view of an implanted sample at a dose of 1 x 1016/cm2. A wide implanted layer is buried at a maximum depth of 4μm with a slightly damaged top surface. The buried layer appears as a highly disordered crystalline structure when the sample was annealed, whereas it is amorphous in an as-implanted sample.

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

A tilting high temperature gas reaction chamber for the JEM 7A T.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 70-71
Author(s):  
Brian L. Rhoades
Keyword(s):  
Cross Section ◽  
Reaction Chamber ◽  
Objective Lens ◽  
Reduced Cross Section ◽  
Cross Sectional ◽  
Structural Investigations ◽  
Transmission Electron ◽  
Dynamic Experiments ◽  
Successful Design ◽  
Thermocouple Junction

A gas reaction chamber has been designed and constructed for the JEM 7A transmission electron microscope which is based on a notably successful design by Hashimoto et. al. but which provides specimen tilting facilities of ± 15° aboutany axis in the plane of the specimen.It has been difficult to provide tilting facilities on environmental chambers for 100 kV microscopes owing to the fundamental lack of available space within the objective lens and the scope of structural investigations possible during dynamic experiments has been limited with previous specimen chambers not possessing this facility.A cross sectional diagram of the specimen chamber is shown in figure 1. The specimen is placed on a platinum ribbon which is mounted on a mica ring of the type shown in figure 2. The ribbon is heated by direct current, and a thermocouple junction spot welded to the section of the ribbon of reduced cross section enables temperature measurement at the point where localised heating occurs.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

Transmission Electron Microscopy Studies of Aluminum Oxidation

1985 ◽  
Vol 43 ◽  
pp. 268-269
Author(s):  
J.Y. Lee
Keyword(s):  
Nucleation And Growth ◽  
Ion Milling ◽  
Cross Sectional ◽  
Polycrystalline Aluminum ◽  
Axis Orientation ◽  
Temperature Oxidation ◽  
Aluminum Oxidation ◽  
Transmission Electron ◽  
High Resolution Images ◽  
Argon Ion

In the oxidation of metals and alloys, microstructural features at the atomic level play an important role in the nucleation and growth of the oxide, but little is known about the atomic mechanisms of high temperature oxidation. The present paper describes current progress on crystallographic aspects of aluminum oxidation. The 99.999% pure, polycrystalline aluminum was chemically polished and oxidized in 1 atm air at either 550°C or 600°C for times from 0.5 hr to 4 weeks. Cross-sectional specimens were prepared by forming a sandwich with epoxy, followed by mechanical polishing and then argon ion milling. High resolution images were recorded in a <110>oxide zone-axis orientation with a JE0L JEM 200CX microscope operated at 200 keV.

Comparison of Ion-Milling Techniques For Cross-Sectional TEM of Semiconductors

1985 ◽  
Vol 43 ◽  
pp. 166-167
Author(s):  
Julia T. Luck ◽  
C. W. Boggs ◽  
S. J. Pennycook
Keyword(s):  
Analytical Techniques ◽  
Sample Surface ◽  
Ion Milling ◽  
Cross Sectional ◽  
Reliable Technique ◽  
Near Surface ◽  
Transmission Electron ◽  
Thin Region ◽  
Transient Thermal

The use of cross-sectional Transmission Electron Microscopy (TEM) has become invaluable for the characterization of the near-surface regions of semiconductors following ion-implantation and/or transient thermal processing. A fast and reliable technique is required which produces a large thin region while preserving the original sample surface. New analytical techniques, particularly the direct imaging of dopant distributions, also require good thickness uniformity. Two methods of ion milling are commonly used, and are compared below. The older method involves milling with a single gun from each side in turn, whereas a newer method uses two guns to mill from both sides simultaneously.

Ion thinning of integrated circuit transverse specimens for transmission electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1426-1427
Author(s):  
F. Shaapur
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Integrated Circuit ◽  
Substrate Surface ◽  
Homogeneous Material ◽  
Material System ◽  
Ion Milling ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Motion Profile

Non-uniform ion-thinning of heterogenous material structures has constituted a fundamental difficulty in preparation of specimens for transmission electron microscopy (TEM). A variety of corrective procedures have been developed and reported for reducing or eliminating the effect. Some of these techniques are applicable to any non-homogeneous material system and others only to unidirectionalfy heterogeneous samples. Recently, a procedure of the latter type has been developed which is mainly based on a new motion profile for the specimen rotation during ion-milling. This motion profile consists of reversing partial revolutions (RPR) within a fixed sector which is centered around a direction perpendicular to the specimen heterogeneity axis. The ion-milling results obtained through this technique, as studied on a number of thin film cross-sectional TEM (XTEM) specimens, have proved to be superior to those produced via other procedures.XTEM specimens from integrated circuit (IC) devices essentially form a complex unidirectional nonhomogeneous structure. The presence of a variety of mostly lateral features at different levels along the substrate surface (consisting of conductors, semiconductors, and insulators) generally cause non-uniform results if ion-thinned conventionally.

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