Formation and Device Application of Ge Nanowire Heterostructures via Rapid Thermal Annealing

Figure 12

(a) TEM image of a fragmented Ni₃Ge nanowire on the TEM grid upon 650°C annealing. (b) HRTEM image of the Ni₃Ge/Ge/Ni₃Ge nanowire heterostructure showing a clean and sharp interface. (c) Lattice-resolved HRTEM image of the Ni₃Ge/Ge interface. The measured lattice mismatch was only 1.5% at the Ni₃Ge(111)/Ge(111) interface. As a result, the twisted growth mode, which was observed in both Ni₂Ge/Ge/Ni₂Ge and Ni₂Ge/NiGe/Ge/NiGe/Ni₂Ge nanowire heterostructures to accommodate the large lattice mismatch, did not occur in this Ni₃Ge/Ge/Ni₃Ge nanowire heterostructure. (d) SEM image showing a broken Ge nanowire upon 650°C RTA due to a low melting pointing of the Ge nanowire. Reproduced from [13].

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