UV laser-based process for quantum well intermixing of Ⅲ-Ⅴ heterostructures

摘要

The influence of surface irradiation of GaAs with a KrF excimer laser on the magnitude of a quantum well (QW) intermixing effect has been investigated in GaAs/AlGaAs QW heterostructures. The irradiation was carried out in an atmospheric environment with laser pulses of fluence between 60 and 90 mJ/cm~2. Following the irradiation, the samples were annealed in a rapid thermal annealing furnace at temperatures ranging from 850 to 925 °C. Compared with non-irradiated samples, a strong suppression of the bandgap shift has been observed in all laser irradiated samples. The suppression increased from 5 to 22 nm for samples irradiated with 88 mJ/cm~2 pulses and annealed at 850 and 900 °C, respectively. This increased thermal stability of excimer laser irradiated samples indicates the potential for developing a process for selective area bandgap engineering of large area GaAs/AlGaAs QW wafers.