Neutron Depth Profiles of Boron Implanted Semiconductors

1989 ◽  
Vol 166 ◽  
Author(s):  
Robert C. Bowman ◽  
John F. Knudsen ◽  
R. Gregory Downing
Keyword(s):  
Depth Profile ◽  
Depth Profiles ◽  
Computer Codes ◽  
Neutron Depth Profile

ABSTRACTThe nondestructive neutron depth profile (NDP) technique has been used to measure boron (10B) distributions in Si and Hg0.7Cd0.3 Te after multiple energy ion implants. The NDP results are compared with simulations generated by TRIM and SUPREM computer codes. The influence of SiO2 films on the boron profiles was examined and the effects of thermal anneals are also described.

Point Contact Current Voltage Measurements of 4H-SiC Samples with Different Doping Profiles

2017 ◽  
Vol 897 ◽  
pp. 287-290 ◽  
Author(s):  
Matthias Kocher ◽  
Michael Niebauer ◽  
Mathias Rommel ◽  
Volker Haeublein ◽  
Anton J. Bauer
Keyword(s):  
Epitaxial Layer ◽  
Depth Profile ◽  
Point Contact ◽  
Surface Preparation ◽  
Epitaxial Layers ◽  
Depth Profiles ◽  
Current Voltage ◽  
Measured Resistance ◽  
Doping Profiles ◽  
Good Agreement

Point contact current voltage (PCIV) measurements were performed on 4H-SiC samples, both for n- an p-doped epitaxial layers as well as samples with rather shallow doping profiles realized by N- or Al-implantation in a range from 1016 cm-3 to 1019 cm-3. Surface preparation and measurement parameters were investigated in order to determine their influence on the measured resistance profiles. Furthermore depth profile measurements were performed on both an epitaxial layer as well as on implanted samples. These depth profiles could be measured reproducibly and showed good agreement with expected profiles for Al-implanted samples as well as for epitaxial layer whereas for N-implanted samples deviations between measured and expected profiles could be observed. It could be proven that PCIV profiling technique is a promising method for characterizing doped profiles in 4H-SiC, especially on Al-implanted samples.

scholarly journals Implications of the form of the Flow Law for Vertical Velocity and Age–Depth Profiles in Polar Ice

1986 ◽  
Vol 32 (112) ◽  
pp. 366-370 ◽  
Author(s):  
E.W. Wolff ◽  
C.S.M. Doake
Keyword(s):  
Velocity Profile ◽  
Depth Profile ◽  
Vertical Velocity ◽  
Experimental Error ◽  
Ice Sheet ◽  
Polar Ice ◽  
Depth Profiles ◽  
Devon Island ◽  
Vertical Velocity Profile ◽  
Flow Law

AbstractTwo situations are studied in relation to the flow law of polar ice. In each case, models are used with a flow-law exponent of one, and with the more traditional exponent of three. The horizontal velocity profile at Devon Island, Arctic Canada, is better fitted byn= 1; for the vertical velocity profile,n= 3 gives a better fit, but both model profiles fall well within experimental error. For the Camp Century age–depth profile, onlyn= 1 gives an acceptable fit when temperature is allowed for. The large discrepancy between isothermal and non-isothermal models forn= 3 shows the importance of allowing for temperature in studies of ice-sheet properties.

scholarly journals Effect of Different Manufacturing Process Steps on the Final Residual Stress Depth Profile along the Process Chain of Autofrettaged Thick-Walled-Cylinders

2014 ◽  
Vol 996 ◽  
pp. 676-681 ◽  
Author(s):  
Horst Brünnet ◽  
Michael Hofmann ◽  
Nataliya Lyubenova ◽  
Dirk Bähre
Keyword(s):  
Residual Stress ◽  
Depth Profile ◽  
Manufacturing Process ◽  
Compressive Residual Stress ◽  
Design Tool ◽  
Process Chain ◽  
Technical Process ◽  
Depth Profiles ◽  
The Impact ◽  
Compressive Residual Stresses

Selectively induced compressive residual stress depth profiles are gaining increasing importance as design tool for internally pressurized components. Hydraulic Autofrettage (AF) is a well-known manufacturing process to induce pronounced compressive residual stresses. However, AF does not stand alone in the technical process chain. In this paper, results from neutron diffraction experiments performed on thick-walled cylinders are presented and compared to finite-element simulations with Abaqus/CAE. The impact on the final residual stress depth profile after pre-machining, Autofrettage and post-machining is discussed.

Depth Profile of Doping Concentration in Thick (> 100 μm) and Low-Doped (< 4 × 1014 cm-3) 4H-SiC Epilayers

2017 ◽  
Vol 897 ◽  
pp. 83-86 ◽  
Author(s):  
Keisuke Fukada ◽  
Naoto Ishibashi ◽  
Yoshihiko Miyasaka ◽  
Akira Bandoh ◽  
Kenji Momose ◽  
...  
Keyword(s):  
Depth Profile ◽  
Gas Flow ◽  
Doping Concentration ◽  
Chemical Vapor ◽  
Constant Depth ◽  
Depth Profiles ◽  
Dopant Incorporation ◽  
In Doping ◽  
Precursor Decomposition ◽  
Reactor Temperature

The depth profiles of n-type doping concentration in thick (>100 μm) and low-doped (< 4 × 1014 cm-3) 4H-SiC epilayers grown by chemical vapor deposition (CVD) were investigated. The variation in doping concentration during epitaxial growth are considered to be caused by: (1) variation in gas flow due to parasitic deposition, (2) variation in precursor decomposition rate due to change in reactor temperature, (3) variation in dopant incorporation rate due to change in wafer temperature, and (4) variation in supply of background dopants. By controlling all these parameters, a constant depth profile in thick (> 100um) epilayers was realized.

scholarly journals Temperature investigation and modeling on the Filchner-Ronne Ice Shelf, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 377-385 ◽  
Author(s):  
K. Grosfeld ◽  
F. Thyssen
Keyword(s):  
Depth Profile ◽  
Basal Layer ◽  
Melting Rate ◽  
Ice Shelf ◽  
Depth Profiles ◽  
Steady State Temperature ◽  
Antarctic Expedition ◽  
Field Season ◽  
Basal Melting ◽  
Temperature Depth

During the German Antarctic Expedition field season 1989–90. hotwater drilling was undertaken on the Filchner-Ronne Ice Shelf (FRIS) at 77° S 52°c W to investigate the temperature-depth profile and the bottom-melting rate, which arc significant parameters for mass- and energy-balance studies of the ice shelf. Remeasurements of installed chains in 1991-92 yie1ded reliable results.Taking glaciological, geodetic and geophysical data on a flowline through the central part of FRIS. we developed a two-dimensional thermal model to reconstruct the measurernents from a steady-state temperature depth profile about 550 km upstream on Möllereisstrom. Considering mass and energy conservation, a basal layer of 350 m of marine ice was calculated with thermal properties, depending on salinity and temperature. In areas with strong basal freezing, almost isothermal depth profiles in the marine ice layer are derived. Further downstream, in areas of basal melting, a nearly cubic temperarure-depth profile is observed.

Applied-Information Technology in Concentration Depth Profile of Multi-Charged Mo Ion Implantation

2014 ◽  
Vol 662 ◽  
pp. 115-118
Author(s):  
Jian Hua Yang ◽  
Xing Jian Ma
Keyword(s):  
Monte Carlo ◽  
Ion Implantation ◽  
Depth Profile ◽  
High Dose ◽  
H13 Steel ◽  
Depth Profiles ◽  
Concentration Depth Profile ◽  
Charged Ions ◽  
Concentration Depth Profiles ◽  
Better Than

Monte Carlo computer simulations based on the binary collision approximation, TRIDYN program, have been applied to calculate the concentration depth profiles of implanted multi-charged molybdenum ions in H13 steel. The sputtering effect of a high dose ion implantation and influence of multi-charged ions on the concentration depth profile of implanted molybdenum ions can both be considered in the TRIDYN simulation. For the Monte Carlo computer simulation, the chosen pseudo-projectiles are 500000. The chosen extraction voltages are 48kV and 25kV, respectively, and an implantation doses of 5×1017cm-2 to compare the results which have been published related to molybdenum ion implantation. TRIDYN program is better than SRIM program in the calculation of the concentration depth profiles of implanted multi-charged ions. And the calculation result of the TRIDYN program is different from the experiment result. The other factors of affecting the concentration depth profile have also been discussed finally.

scholarly journals Residual stress and strain-free lattice-parameter depth profiles in a γ′-Fe4N1-x layer on an α-Fe substrate measured by x-ray diffraction stress analysis at constant information depth

2009 ◽  
Vol 24 (4) ◽  
pp. 1342-1352 ◽  
Author(s):  
M. Wohlschlögel ◽  
U. Welzel ◽  
E.J. Mittemeijer
Keyword(s):  
Residual Stress ◽  
Stress Analysis ◽  
Depth Profile ◽  
Nitrogen Concentration ◽  
Lattice Parameter ◽  
Free Lattice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Grain Interaction

The residual stress and lattice-parameter depth profiles in a γ′-Fe4N1-x layer (6-μm thickness) grown on top of an α-Fe substrate were investigated using x-ray diffraction stress analysis at constant penetration depths. Three different reflections (220, 311, and 222) were recorded at six different penetration depths using three different wavelengths. At each penetration depth, x-ray diffraction stress analysis was performed on the basis of the sin2ψ method. As a result, the residual-stress depth profile was obtained from the measured lattice strains. The lattice spacings measured in the strain-free direction were used to determine the (strain-free) lattice-parameter depth profile. The nitrogen-concentration depth profile in the layer was calculated by applying a relationship between the (strain-free) γ′ lattice parameter and the nitrogen concentration. It was found that the strain-free lattice-parameter depth profile as derived from the 311 reflections is best compatible with nitrogen concentrations at the surface and at the γ′/α interface as predicted on the basis of local thermodynamic equilibrium. It could be shown that the 311 reflection is most suitable for the analysis of lattice-parameter and residual stress depth profiles because the corresponding x-ray elastic constants exhibit the least sensitivity to the type of and changes in grain interaction. The depth-dependence of the grain interaction could be revealed. It was found that the grain interaction changes from Voigt-type near the surface to Reuss-type at the layer/substrate interface.

Seed-bank properties of an Appalachian sphagnum bog and a model of the depth distribution of viable seeds

1987 ◽  
Vol 65 (10) ◽  
pp. 2028-2035 ◽  
Author(s):  
James B. McGraw
Keyword(s):  
Depth Profile ◽  
Seed Bank ◽  
Soil Surface ◽  
High Elevation ◽  
Seed Rain ◽  
Historical Change ◽  
Seed Burial ◽  
Depth Profiles ◽  
A Minor ◽  
Sphagnum Bog

Seed banks were examined in four plant communities in a high-elevation sphagnum bog in West Virginia, U.S.A. A germination assay was used to detect germinable seed densities. Vertical depth distributions were determined for one community in which the soil cores were transported intact to the greenhouse. Seed densities ranged from 12 874 in a Sphagnum-dominated community to 377 041 seeds m−2 in a sedge-dominated community. The seed bank in all communities was dominated numerically by Juncus effusus, although this species comprised a minor part of the aboveground vegetation. Three types of depth profiles were observed, including one distribution showing a simple decline in seed numbers with depth, another showing a unimodal peak below the soil surface, and a third with two distinct peaks at depth. A matrix model of seed burial was devised to account for the different depth profiles. By assuming that soil compression occurred and that the rate of compression declined with time, the model showed that either of the first two depth profiles could be produced with no need to invoke a historical change in the seed rain. The model was unable to account for the bimodal depth profile with the assumption of a constant seed rain. However, the fact that the model of seed burial could explain a unimodal peak in the depth profile suggests that simple historical interpretations of past abundance using a buried seed profile are difficult.

Depth Measurement of Dislocations in Si Substrate by Stereo TEM

2005 ◽  
Author(s):  
Jong-Shing Bow ◽  
Speed Yu
Keyword(s):  
Depth Profile ◽  
Reference Line ◽  
Si Substrate ◽  
Depth Measurement ◽  
Depth Profiles ◽  
Plane View ◽  
3D Shapes ◽  
Local Depth

Abstract Traditional plane-view TEM images, which have large fields of view and are usually used to check the existence of dislocations, cannot tell whether a dislocation goes through the p-n junction or not. While XTEM images tell the local depth of a small part of a dislocation only, other methods have to be developed to explore how a dislocation goes in the substrate. In this article, the authors have modified the technique of stereo TEM, which was used to study the 3D shapes of precipitates, to study how a dislocation runs in the Si substrate. Three images recorded after tilting the TEM sample were used for measuring the dislocation depth profile. The distances between a few chosen points on the dislocation and the reference line were measured from above three images. Results suggested that the depth profiles of dislocations in the Si substrate can be accurately determined by stereo TEM.

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