Low-resistance ohmic contacts to AlGaAs/GaAs and In0.52Al0.48As/In0.53Ga0.47As modulation-doped structures obtained by halogen lamp annealing

The successful application of short-term halogen lamp annealing to form ohmic contacts to AlGaAs/GaAs and In 0.52 Al 0.48 As/ In 0.53 Ga 0.47 As modulation-doped structures is demonstrated. Use of Ti in the electron-beam evaporated metallization scheme and a two-step annealing cycle give contacts with reproducibly good electrical and morphological characteristics. Minimum values of specific contact resistance ρc = 4.0 × 10⁻⁷ and 6.0 × 10⁻⁷ Ω.cm2for AlGaAs/GaAs and In 0.52 Al 0.48 As/In 0.53 Ga 0.47 As, respectively, are measured. Corresponding values of the transfer resistance R c are 0.12 ± 0.02 and 0.18 ± 0.05 Ω.mm. These values are the lowest achieved with lamp annealing and are comparable to the best obtained with transient furnace annealing.