A comprehensive study of Ge1−xSix on Ge for the Ge nMOSFETs with tensile stress, shallow junctions and reduced leakage

For the first time, growth of high-quality Ge-rich Ge_1-xSi_x (0 ¿ × ¿ 0.14) layers on Ge substrate was demonstrated. An effective suppression of the phosphorus diffusion in Ge_1-xSi_x and a better thermal stability of the nickel germanide on Ge_1-xSi_x were observed. A higher rectifying ratio with a reduced diode leakage current in n⁺-Ge_1-xSi_x/p-Ge_1-xSi_x is compared with n⁺-Ge/p-Ge. These results indicate that it is suitable for Ge_1-xSi_x to be used as source/drain (S/D) to fabricate the uniaxial tensile-strained channel Ge nMOSFETs.