Journal of Vacuum Science & Technology A, Vol.22, No.3, 887-890, 2004
Laser-induced selective area tuning of GaAs/AlGaAs quantum well microstructures for two-color IR detector operation
Selective area laser annealing of GaAs/AlxGa1-xAs quantum well infrared photodetector (QWIP) material has been investigated as a possible route towards the fabrication of two-color low-cost focal plane array devices. Tuning of the wavelength response of the material has been achieved as a consequence of the quantum well intermixing (QWI) effect. A 90 s irradiation with a continuous wave Nd:yttrium-aluminum-garnet laser, at the peak temperature of 850degreesC, resulted in the 40 nm blueshift of the QW photoluminescence peak from 832 to 792 nm. This corresponded to the 0.7 mum redshift of the wavelength response of the investigated QWIP microstructure in the 8 Am optical absorption region. The amplitude of this shift is consistent with the literature data obtained for similar material processed directly by rapid thermal annealing (RTA) or by a two-step process involving particle implantation and RTA. We have examined the laser-QWI approach for direct writing of arrays of a two-band gap material. The preliminary results indicate the feasibility of this approach for fabricating linear arrays with a period of 0.8 mm. (C) 2004 American Vacuum Society.