To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
4H SiC is a promising material because of its mechanical, electrical, and physical properties. However, SiC material defects have had a rate limiting effect on the widespread adoption of SiC. Micropipes, basal plane dislocations (BPD), elementary screw dislocations (SDD) and threading edge dislocations (TED) have all been identified as limiting to device operation and/or performance. An ideal PVT strategy for manufacturing SiC crystals would be capable of driving defects out the crystal via a combination of thermal field control and defect dissociation pathways. In this work a PVT technology was realized which is capable of continuously improving the crystal quality. A low defect PVT process was conceived and optimized using iterative experiment and simulation methods. During the maturation of the process it was observed that the crystal defect density repeatedly decreased relative to the seed crystal, as evaluated by x-ray topography, x-ray diffraction, and molten salt etching. The process improvements were leveraged successfully to achieve 4H n+ SiC wafers at 76-100 mm diameter with MPD <1 cm-2, SDD <500 cm-2, and BPD <500 cm-2. This paper will illustrate the defect reduction pathways leading to state of the art defect density 4H SiC crystals and the impact of the improved crystal on epitaxy defects and simple device experiments.
Below is the complete Reference citation for Hoffmann et al.
Hoffmann, D.H.H., Blazevic, A., Ni, P., Rosmej, O., Roth, M.,
Tahir, N., Tauschwitz, A., Udrea, S., Varentsov, D., Weyrich, K. &
Maron, Y. (2005). Present and future perspectives for high energy
density physics with intense heavy ion and laser beams. Laser Part.
The study of heavy ion stopping dynamics using associated K-shell
projectile and target radiation was the focus of the reported experiments.
Ar, Ca, Ti, and Ni projectile ions with the initial energies of 5.9 and
11.4 MeV/u were slowed down in quartz and arogels. Characteristic
radiation of projectiles and target atoms induced in close collisions was
registered. The variation of the projectile ion line Doppler shift due to
the ion deceleration measured along the ion beam trajectory was used to
determine the ion velocity dynamics. The dependence of the ion velocity on
the trajectory coordinate was measured over 70–90% of the ion beam
path with a spatial resolution of 50–70 μm. The choice of
SiO2 aerogel with low mean densities of 0.04–0.15
g/cm3 as a target material, made it possible to stretch the
ion stopping range by more than 20–50 times in comparison with solid
quartz. It allowed for resolving the dynamics of the ion stopping process.
Experimentally, it has been proven that the fine porous nano-structure of
aerogels does not affect the ion energy loss and charge state
distribution. The strong increase of the ion stopping range in aerogels
made it possible to resolve fast ion radiation dynamics. The analysis of
the projectile Kα-satellites structure allows supposing that ions
propagate in solid in highly exicted states. This can provide an
experimental explanation for so called gas-solid effect.
Email your librarian or administrator to recommend adding this to your organisation's collection.