The European Physical Journal Applied Physics

Table of Contents - July 2004 - Volume 27, Issue 1-3 (Tenth International Conference on Defects: Recognition, Imaging and Physics in Semiconductors (DRIP X))  

Defect mapping over large area wafers

Contact-free investigation of the EL2-defect in the surface of GaAs wafers

B. Gründig-Wendrocka1, K. Dornicha1, T. Hahna1, U. Kretzera2 and J. R. Niklasa1

Institute of Experimental Physics, TU Bergakademie Freiberg, Silbermannstr. 1, Freiberg, 09599, Germany

Freiberger Compound Materials GmbH, Am Junger Löwe Brunnen 5, Freiberg, 09599, Germany

Abstract

The EL2 as the most important intrinsic defect in semi-insulating GaAs was already deeply studied in the past. All investigation methods applied so far to semi-insulating GaAs explore the entire depth of the sample and are therefore not suitable to analyse e.g. influences of surface treatments. In this work the detection of EL2 in the surface of samples by the application of microwave detected photo induced current transient spectroscopy will be presented. A correlation between height and sign of the signals and the concentration of acceptors, furthermore of the compensation ratio of the EL2, the position of the Fermi level as well as the specific resistivity was found. The results can be simulated by solving rate equations for the measurement process.

(Received September 9 2003)

(Accepted January 28 2004)

(Online publication July 15 2004)

PACS:

  • 71.55.Eq – III-V semiconductors;
  • 72.20.Jv – Charge carriers: generation, recombination, lifetime, and trapping

bianca_gruendig@web.de