SAIP2017

Investigation of defects in sputter deposition deposited Schottky barrier diodes on epitaxial GaAs by Laplace DLTS

5 Jul 2017, 17:10

1h 50m

3rd and 4th floor passages (Engineering Building 51)

Board: 09

Poster Presentation Track A - Division for Physics of Condensed Matter and Materials Poster Session 2

Speaker

Ms Fatemeh Taghizadeh (University of Pretoria)

Description

High resolution deep level transient spectroscopy (Laplace DLTS) was used to study Si doped n-type epitaxial GaAs. In this work, we used Au as the target material for the deposition of GaAs samples by sputtering deposition system. Three different doping densities of GaAs (1x10¹⁵ cm^-3, 1x10¹⁶ cm^-3 and 8x10¹⁶ cm^-3) were deposited with 3 different powers 100 W, 150 W and 200 W for 10 minutes. From the Arrhenius plot, we found 3 defects with deferent energy levels (0.58 eV, 0.50 eV and 0.31 eV). The E_c- 0.50 eV defect is dopant dependent while the other two (0.58 eV and 0.31 eV) did not involve dopant atom. The E_c - 0.58 defect is bistable with the E_c - 0.31 eV defect, Under 0 V bias for 5 minutes, the E_c - 0.31 eV transforms to E_c - 0.58 eV and by applying the reverse bias the E_c - 0.58 eV transforms to E_c - 0.31 eV. This transformation is completely reversible. These results are the same as the results achieved by inductivity coupled plasma etching of GaAs [1]. The results from current-voltage measurements indicate that current reverse is a substantially higher compared to that of resistivity evaporated Schottky diodes.

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

No

Main supervisor (name and email)<br>and his / her institution

Professor F.D.Auret

danie.auret48@gmail.com

University of Pretoria (UP)

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD, N/A)?

PhD

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

Yes