Two-step hydrogen-ion implantation annihilation of threading dislocation defects in strain-relaxed Si0.7Ge0.3

Abstract

We propose a two-step hydrogen-ion implantation approach for realizing crystalline-defect-free Si1-xGex channels for potential use in gate-all-around field-effect-transistors beyond the 3 nm transistor-design rule. A dislocation sink was created in a projected range of ion implantation 100 and 200 nm above the strain-relaxed Si0.7Ge0.3 layer and Si substrate interface using two-step H+ -ion implantation. Doses of 5 x 10(15) and 2 x 10(15) atoms/cm(2) were used at 100 and 200 nm, respectively, above the interface, and post-annealing was performed at 800 degrees C for 30 min. The two-step implantation annihilated the misfit and threading dislocations near the relaxed Si0.7Ge0.3/Si interface. The annihilation efficiency strongly depended on the location and second ion dose of the implantation: the maximum annihilation efficiency was obtained at 100 and 200 nm above the interface with multiple H+-ion doses of 5 x and 2 x 10(15) atoms/cm(2).