About the Capability of the Low-Power Pulsed-Laser Annealing to recover the Structural Damage Induced by Ion-Implantation IN III-V Semiconductors

It is very well known that the characteristics of GaAs render it promising to manufacture high speed devices. In any case the GaAs is not simple considering, first of all, that one of the components (As) can be loosed in a preferential way over a critical temperature (Tc=600 °C) with a consequent stoichiometric alteration. In spite of this, the conventional annealing techniques ( after the ion implantation process) involve temperature higher than Tc compelling the producer to use some stratagems which rise the device cost. In the last few years it has been pointed out the possibility to apply the Low-Power Pulsed-Laser Annealing (LPPLA). process to low dose ion implanted GaAs. The effects have been analyzed with different experimental techniques such as TEM (Transmission Electron Microscopy) , RHEED (Reflection High Energy Electron Diffraction) and RBS (Rutherford Backscattering Spectroscopy). The complementary results of these analysis techniques showed the existence of an energy-laser window in which the LPPLA is effective to recover the crystalline order, avoiding the critical temperature exceeding. We report here: 1) the XPS measurements confirming the presence of the energy window and, moreover, revealing that the structural recover is reached without any residual surface stoichiometric alteration; 2) the electrical measurements (sheet resistivity and mobility) showing how is possible by LPPLA to obtain a sheet resistivity reduction and mobility increase.