RBS channeling spectroscopy of Ge implanted epitaxial Si_1-x Ge_x layers

Si_1-xGe_x layers were formed through high-dose germanium ion implantation into (100)Si substrates. Two alternative implantation techniques along with that of the single-energy Ge⁺ implantation were separately adopted: the double-energy Si⁺ and Ge⁺ method, and the double-energy Ge⁺ and Ge⁺⁺ method. The purpose of the both double-energy methods was to form deeper amorphous layers by using relatively low-dose Si⁺ or Ge⁺⁺ ion bombardment while the SiGe alloy layers were created by high dose Ge⁺ ion implantations. Furthermore, all the amorphized samples were epitaxialy regrown by conventional furnace annealing at temperature of 525 to 600°C. RBS channeling spectroscopy was used for optimizing these implantation processes. Measurements confirm that the double-energy Ge⁺ and Ge⁺⁺ method is optimum because of generating fewer residual defects. Additionally, the preliminary result on the regrowth properties of the double-energy Ge⁺ and Ge⁺⁺ implanted SiGe layer is also presented.