Defect and electrical characterization
of bulk semi-insulating (SI) 4H-SiC crystals and SI and
n-type 4H-SiC epitaxial layers grown by chemical vapor deposition
(CVD) on highly doped (0001) 4H-SiCsubstrates is reported. Optical
microscopy, electron beam induced current (EBIC) imaging, current-voltage ($I$–$V$)
measurements, thermally stimulated current (TSC) spectroscopy (94 K–620 K),
Hall effect, and van der Pauw measurements have been conducted for
characterization and defect correlation studies. Both epitaxial layers
exhibited relatively shallow levels related to Al, B, $L$ - and
D-centers. Deep level centers in the n-type epitaxial layer peaked at ${sim}
400$ K ($E_{a} sim 1.1$ eV), and ${sim}
470$ K were correlated with $IL_{2}$ defect and 1.1 eV center in high-purity bulk SI 4H-SiC.
The SI epitaxial layer exhibited peak at ${sim} 290$ K ( $E_{a} = 0.82hbox{--}0.87$ eV) that was attributed to $IL_{1}$ and
HK2 centers, and at ${sim} 525$ K that
was related to intrinsic defects and their complexes with energy levels close
to the middle of the band-gap. Results of EBIC and optical microscopy showed
segregation of threading dislocations around comet tail defects in the n-type
epitaxial layer. The $I$– $V$ characteristics of the devices on SI epitaxial layer exhibited steps
corresponding to the ultimate trap filling of deep centers. The
high-temperature resistivity measurements of bulk SI 4H-SiC sample
revealed resistivity hysteresis that was attributed to the filling of the
deep-level electron trap centers. The responsivity of the n-type
epitaxial 4H-SiC detector in the soft X-ray energy range is reported
for the first time.
Source:IEEE
If you need more information about Characterization of 4H-SiC Epitaxial Layers and
High-Resistivity Bulk Crystals for Radiation Detectors, please visit
our website:http://www.qualitymaterial.net, send us email at powerwaymaterial@gmail.com.
Thanks for sharing such an interesting post that helps to understand the radiation and about radiation detectors.For radiation detector for sale
ReplyDelete