Alternative Highly Homogenous Drift Layer Doping for 650 V SiC Devices

A new method for homogenous drift layer doping is introduced. Instead of in-situ doping during epitaxial growth a subsequent high energy ion implant step is used to dope the drift layer of 650V MPS (Merged-PN-Schottky) diodes. In order to avoid multiple implant steps with various energies for emulating a box-like doping profile, a novel “energy filter” membrane is used to transform the monochromatic ion beam to a beam with a continuous energy spectrum suited for box-like doping. The electrical characteristics of the diodes manufactured by this means show a very homogenous blocking behavior on wafer level, however the expected improved homogeneity in differential resistance of the wafers could not be confirmed by wafer level measurements. More work is needed to understand this discrepancy between experiment and theory.

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Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155232 ◽

1989 ◽

Vol 47 ◽

pp. 652-653

Author(s):

Charles W. Allen ◽

Robert C. Birtcher

Keyword(s):

Elevated Temperatures ◽

Ion Irradiation ◽

Ion Beam ◽

National Laboratory ◽

Argonne National Laboratory ◽

Heavy Ion ◽

High Energy ◽

Mechanical Twinning ◽

In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

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Low Voltage High-Energy α-Particle Detectors by GaN-on-GaN Schottky Diodes with Record-High Charge Collection Efficiency

Sensors ◽

10.3390/s19235107 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5107 ◽

Cited By ~ 3

Author(s):

Sandupatla ◽

Arulkumaran ◽

Ranjan ◽

Ing ◽

Murmu ◽

...

Keyword(s):

Low Voltage ◽

Collection Efficiency ◽

Schottky Diodes ◽

High Energy ◽

Charge Collection ◽

Charge Carrier Density ◽

Free Standing ◽

Charge Collection Efficiency ◽

High Charge ◽

Drift Layer

A low voltage (–20 V) operating high-energy (5.48 MeV) α-particle detector with a high charge collection efficiency (CCE) of approximately 65% was observed from the compensated (7.7 × 1014 /cm3) metalorganic vapor phase epitaxy (MOVPE) grown 15 µm thick drift layer gallium nitride (GaN) Schottky diodes on free-standing n+-GaN substrate. The observed CCE was 30% higher than the bulk GaN (400 µm)-based Schottky barrier diodes (SBD) at –20 V. This is the first report of α–particle detection at 5.48 MeV with a high CCE at –20 V operation. In addition, the detectors also exhibited a three-times smaller variation in CCE (0.12 %/V) with a change in bias conditions from –120 V to –20 V. The dramatic reduction in CCE variation with voltage and improved CCE was a result of the reduced charge carrier density (CCD) due to the compensation by Mg in the grown drift layer (DL), which resulted in the increased depletion width (DW) of the fabricated GaN SBDs. The SBDs also reached a CCE of approximately 96.7% at –300 V.

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Orientational and Microstructural Evolution During Epitaxial Growth of Cu on Si(001) by Sputter Deposition

MRS Proceedings ◽

10.1557/proc-280-327 ◽

1992 ◽

Vol 280 ◽

Cited By ~ 3

Author(s):

I. Hashim ◽

B. Park ◽

H. A. Atwater

Keyword(s):

Epitaxial Growth ◽

Ion Beam ◽

High Energy ◽

Sputter Deposition ◽

X Ray Diffraction ◽

Cross Sectional ◽

Plan View ◽

Transmission Electron

ABSTRACTEpitaxial Cu thin films have been grown on H-terminated Si(OOl) substrates at room temperature by D.C. ion-beam sputter deposition in ultrahigh vacuum. The development of orientation and microstructure during epitaxial growth from the initial stages of Cu growth up to Cu thicknesses of few hundred nm has been investigated. Analysis by in-situ reflection high energy electron diffraction, thin film x-ray diffraction, and plan-view and cross-sectional transmission electron microscopy indicates that the films are well textured with Cu(001)∥ Si(001) and Cu[100]∥ Si[110]. Interestingly, it is found that a distribution of orientations occurs at the early stages of Cu epitaxy on Si(001) surface, and that a (001) texture emerges gradually with increasing Cu thickness. The effect of silicide formation and deposition conditions on the crystalline quality of Cu epitaxy is also discussed.

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Radiation-induced disordering and amorphization—An in situ HVEM study of uranium silicide with comparison to natural processes in zirconolite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175806 ◽

1990 ◽

Vol 48 (4) ◽

pp. 534-535

Author(s):

R. C. Birtcher ◽

L. M. Wang ◽

C. W. Allen ◽

R. C. Ewing

Keyword(s):

Electron Irradiation ◽

Ion Irradiation ◽

Ion Beam ◽

National Laboratory ◽

Argonne National Laboratory ◽

Heavy Ion ◽

High Energy ◽

In Situ Tem ◽

In Situ Experiments

We present here results of in situ TEM diffraction observations of the response of U3Si and U3Si2 when subjected to 1 MeV electron irradiation or to 1.5 MeV Kr ion irradiation, and observations of damage occuring in natural zirconolite. High energy electron irradiation or energetic heavy ion irradiation were performed in situ at the HVEM-Tandem User Facility at Argonne National Laboratory. In this Facility, a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter have been interfaced to a 1.2 MeV AEI high voltage electron microscope. This allows a wide variety of in situ experiments to be performed with simultaneous ion irradiation and conventional transmission electron microscopy. During the electron irradiation, the electron beam was focused to a diameter of about 2 μ.m at the specimen thin area. The ion beam was approximately 2 mm in diameter and was uniform over the entire specimen. With the specimen mounted in a heating holder, the temperature increase indicated by the furnace thermocouple during the ion irradiation was typically 8 °K.

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3-D Patterned III-V Semiconductor Devices Using High Energy In-Situ Focused Ion Beam Lithography and MBE

Frontiers in Nanoscale Science of Micron/Submicron Devices ◽

10.1007/978-94-009-1778-1_3 ◽

1996 ◽

pp. 35-39

Author(s):

P. D. Rose ◽

E. H. Linfield ◽

G. A. C. Jones ◽

D. A. Ritchie

Keyword(s):

Focused Ion Beam ◽

Ion Beam ◽

Semiconductor Devices ◽

High Energy ◽

Ion Beam Lithography

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Stability of Uranium Silicides During High Energy Ion Irradiation

MRS Proceedings ◽

10.1557/proc-235-467 ◽

1991 ◽

Vol 235 ◽

Cited By ~ 5

Author(s):

R. C. Birtcher ◽

L. M. Wang

Keyword(s):

Ion Irradiation ◽

Ion Beam ◽

Amorphous State ◽

Temperature Limit ◽

High Energy ◽

Grain Structure ◽

Twin Structure ◽

Fine Grain ◽

Transmission Electron

ABSTRACTChanges induced by 1.5 MeV Kr ion irradiation of both U3Si and U3Si2 have been followed by in situ transmission electron microcopy. When irradiated at sufficiently low temperatures, both alloys transform from the crystalline to the amorphous state. When irradiated at temperatures above the temperature limit for ion-beam amorphization, both compounds disorder, with the Martensite twin structure in U3Si disappearing from view in TEM. Prolonged irradiation of the disordered crystalline phases results in nucleation of small crystallites within the initially large crystal grains. The new crystallites increase in number during continued irradiation until a fine grain structure is formed. Electron diffraction yields a powder-like diffraction pattern that indicates a random alignment of the small crystallites. During a second irradiation at lower temperatures, the small crystallizes retard amorphization. After 2 dpa at high temperatures, the amorphization dose is increased by over twenty times compared to that of initially unirradiated material.

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GHz-Scanning Acoustic Microscopy Combined with ToF-SIMS/AFM for Wafer-Level Failure Analysis of Bonding Interfaces

ISTFA 2019: Conference Proceedings from the 45th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2019p0029 ◽

2019 ◽

Author(s):

Ingrid De Wolf ◽

Ahmad Khaled ◽

Alexis Franquet ◽

Valentina Spampinato ◽

Thierry Conard ◽

...

Keyword(s):

Chemical Analysis ◽

Failure Analysis ◽

Ion Beam ◽

Acoustic Microscopy ◽

Scanning Acoustic Microscopy ◽

Wafer Level ◽

Tof Sims

Abstract This paper discusses the implementation of GHz-Scanning Acoustic Microscopy (GHz-SAM) into a wafer level scanning tool and its application for the detection of delamination at the interface of hybrid bonded wafers. It is demonstrated that the in-plane resolution of the GHz-SAM technique can be enhanced by thinning the sample. In the current study this thinning step has been performed by the ion beam of a ToF-SIMS tool containing an in-situ AFM, which allows not only chemical analysis of the interface but also a well-controlled local thinning (size, depth and roughness).

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Si NWs Conversion to Si-SiC Core-Shell NWs by MBE

Materials Science Forum ◽

10.4028/www.scientific.net/msf.821-823.965 ◽

2015 ◽

Vol 821-823 ◽

pp. 965-969

Author(s):

Fernando Lloret ◽

D. Araujo ◽

M.P. Villar ◽

L. Liu ◽

Konstantinos Zekentes

Keyword(s):

Electron Microscopy ◽

Focused Ion Beam ◽

Ion Beam ◽

High Vacuum ◽

High Energy ◽

Ultra High Vacuum ◽

Si Nanowires ◽

Transmission Electron ◽

Set Up

Si nanowires (NWs) samples have been converted to silicon carbide (SiC) NWs at different conditions of substrate temperature in an ultra-high vacuum using a molecular beam epitaxy (MBE) set-up. Auger electron spectroscopy (AES) and reflection high-energy electron diffraction (RHEED) have been in-situ carried out to control the growth process. Scanning electron microscopy (SEM) and conventional transmission electron microscopy (CTEM) have been used to characterize the resulting nanostructures. In addition, the samples have been prepared by focused ion beam (FIB) in order to have electron-transparently lamellas for TEM with the interface nanowire-substrate. SiC/Si shell/core NWs free of planar defects have been obtained for conversion tmpratures lower than 800oC.

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Argon Ion Bombardment During Molecular Beam Epitaxy of Ge (001)

MRS Proceedings ◽

10.1557/proc-128-35 ◽

1988 ◽

Vol 128 ◽

Cited By ~ 4

Author(s):

Eric Chason ◽

K. M. Horn ◽

J. Y. Tsao ◽

S. T. Picraux

Keyword(s):

Molecular Beam Epitaxy ◽

Surface Morphology ◽

Molecular Beam ◽

Ion Beam ◽

High Energy ◽

Low Energy ◽

High Energy Electron ◽

Argon Ion Bombardment ◽

Argon Ion

ABSTRACTUsing in situ, real-time reflection high energy electron diffraction (RHEED), we have measured the evolution of Ge (001) surface morphology during simultaneous molecular beam epitaxy and Ar ion beam bombardment. Surprisingly, low-energy Ar ions during growth tend to smoothen the surface. Bombardment by the ion beam without growth roughens the surface, but the surface can be reversibly smoothened by restoring the growth beam. We have measured the effect of such “ion beam growth smoothening” above and below the critical temperature for intrinsic growth roughening. At all measured growth temperatures the surface initially smoothens, but below the critical roughening temperature the final surface morphology is rough whereas above this temperature the final morphology is smooth.

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