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The optimized growth conditions for high density germanium(Ge) nanowires and P-doped Ge nanowires on Si(111) substrate were investigated,the phosphorus(P)-doping in Ge nanowires was also characterized.Vapor liquid solid-low pressure chemical vapor deposition(VLS-LPCVD) of Ge nanowires was conducted with different thicknesses of Au film as catalyst,different flow rates of GeH_4 as precursor and PH_3/Ar as co-flow.The morphologies of the Ge nanowires were characterized by scanning electron microscopy(SEM),the P-doping was verified by micro Raman spectroscopy via measuring the P local vibrational peak(342-345 cm~(-1)) and asymmetric broadening of Ge-Ge vibrational peak(about 300 cm~(-1),respectively.The characterization results show that 1 run thickness of Au catalyst is the most suitable condition among thicknesses of 0.1,1,5,and 10 nm for the growth of high density Ge nanowires at 300 and 350℃,and 0.5 sccm is the best flow rate of PH_3/Ar to grow high density and large scale P-doped Ge nanowires among flow rates of 0.5,1 and 2sccm.The P impurity can be doped into Ge nanowires effectively during LPCVD process at 350 ℃.
The optimized growth conditions for high density germanium (Ge) nanowires and P-doped Ge nanowires on Si (111) substrates were investigated, the phosphorus (P) -doping in Ge nanowires was also characterized. Vapor liquid solid-low pressure chemical vapor deposition (VLS-LPCVD) of Ge Nanowires was conducted with different thicknesses of Au film as catalyst, different flow rates of GeH_4 as precursor and PH_3 / Ar as co-flow. The morphologies of the Ge nanowires were characterized by scanning electron microscopy (SEM) , the P-doping was verified by micro Raman spectroscopy via measuring the P local vibrational peak (342-345 cm -1) and asymmetric broadening of Ge-Ge vibrational peak (about 300 cm -1), respectively. The characterization results show that 1 run thickness of Au catalyst is the most suitable condition among thicknesses of 0.1, 1, 5, and 10 nm for the growth of high density Ge nanowires at 300 and 350 ° C., and 0.5 sccm is the best flow rate of PH_3 / Ar to grow high density and large scale P-doped G. The nanowires among flow rates of 0.5, 1 and 2 seem. The P impurity can be doped into Ge nanowires during effective during the LPCVD process at 350 ° C.