Atomic Structure of Deep Level Defects in Dimethylaluminum Methoxide-Doped GaAs

Abstract

AbstractGaAs epilayers doped with dimethylaluminum methoxide (DMA1MO), an alkoxide bearing a pre-formed Al-O molecule, have been investigated using local vibrational mode (LVM) absorption and deep level transient spectroscopy measurements. LVM measurements indicated that oxygen and aluminum atoms are incorporated into GaAs layer as a complex and remain bound in the volume of the crystal. Electron traps with activation energies of 0.74 and 0.93 eV below the conduction band are main deep level defects responsible for the electrical and optical properties of the layers. Interpretation of the relationship between trap concentration and growth conditions led to the conclusion that the 0.93 and 0.74 eV traps have the atomic structures in which oxygen atom is bonded to one (AlO) and two aluminum atoms (A12O), respectively.