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

Figure 7

Plane-view TEM images of Ni-Ge nanowire devices on a TEM grid with a 50 nm thick Si₃N₄ window. (a) Low-magnification TEM image of a Ge nanowire reacted with 120 nm thick Ni pads upon 450°C RTA for 30 s. (b) Enlarged TEM image from the white rectangle in (a). These regions with different contrasts and compositions are labeled. (c) Corresponding EDS line-scan profiles of Ge and Ni across the region between two red lines in (b). (d) Lattice-resolved TEM image of the formed Ni_xGe/Ge nanowire heterostructure from the white rectangle in (b). The labeled lattice spacings are: 𝑑₍₀₀₁₎=0.5036 nm for Ni₂Ge; 𝑑₍₁₀₀₎=0.538 nm and 𝑑₍₀₀₁₎=0.5811 nm for NiGe; 𝑑₍₁₁₁₎=0.3265 nm and 𝑑_(1-1-1)=0.3265 nm for Ge. (e)–(g) are the FFT patterns taken from the Ni₂Ge, NiGe, and Ge regions in (d), respectively. Reproduced from [14].