A comparative study of deep levels created by low dose implantation of hydrogen, oxygen and silicon into MOCVD grown n-GaAs
Electrically active defects created in MOCVD grown n-GaAs by low dose H, O and Si implantation (10 8-10 10 cm -2) are investigated and compared by the deep level transient spectroscopy technique. The only deep level present in the starting material is EL2. H implantation creates fairly simple defects which are easily analysed, namely EL6, EL5, E4, E5 and additional EL2. The more complex U-band is also observed. EL5 traps with an energy level of ( Ec - 0.40) eV, have not previously been reported in H implanted GaAs. This defect is associated with a complex involving impurities. With O and Si implantation, the resulting DLTS spectra are dominated by EL6 and a broad peak corresponding to the so-called U-band. This band is also observed in H implanted samples but to a much lower magnitude. The appearance of the U-band is associated to the interaction between EL2 and EL6 as a result of implantation-induced damage.