Speaker
Dr
Ezekiel Omotoso
(University of Pretoria, Pretoria, South Africa)
Description
We have characterized the deep level defects present before and after proton irradiation and annealing of n-type, N-doped, 4H-SiC using deep level transient spectroscopy (DLTS). The bombardment of the sample was carried out at fluence of 1.0 × 1012 cm–2. The suitability of Schottky barrier diodes (SBDs) was tested before and after proton irradiation and annealing by current–voltage (I-V) and capacitance–voltage (C-V) carried out at room temperature. I-V and C-V results revealed a degradation of the (SBDs) properties after proton irradiation. Rectification properties of the SBDs were restored gradually after annealing in flowing argon at temperatures varies from 125 to 625 °C. Presence of four electron traps (Ec – 0.10, Ec – 0.13, Ec – 0.18 and Ec – 0.69 eV) were observed in as-grown diodes. Deep level defects, Ec – 0.42 and Ec – 0.76 eV, were revealed after annealing the proton-irradiated SBDs up to 225 °C, while Ec – 0.42 eV later annealed out at 425 °C which led to changes in the spectrum shown in Fig. 1. The disappearance of Ec – 0.42 eV also probably led to the appearance of two electron traps (Ec – 0.31 and Ec – 0.62 eV) at annealing temperature of 425 °C. We speculate that the defect Ec – 0.42 eV has a link or relationship with defects Ec – 0.31 and Ec – 0.62 eV, respectively. The defects, Ec – 0.31 eV, remained up to high temperature annealing, has a similar energy with defect Ec – 0.32 obtained after electron irradiation, though unstable, which has been attributed to a carbon interstitial.
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
Prof. W.E. Meyer
University of Pretoria
Apply to be<br> considered for a student <br> award (Yes / No)?
No
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
N/A
Summary
Proton irradiation with 1.8 MeV introduced deep level defects into thermally fabricated Ni/4H-SiC. These defects emanated were characterized by deep level transient spectroscopy. Annealing the irradiated devices revealed the presence of two new defects.
Primary author
Dr
Ezekiel Omotoso
(University of Pretoria, Pretoria, South Africa)
Co-authors
Mr
Alexander Paradzah
(MSc Student)
Prof.
Danie Auret
(University of Pretoria)
Mr
Johan Janse van Rensburg
(University of Pretoria)
Dr
Walter Meyer
(University of Pretoria)