Low Temperature Deposition and Crystallization of Large-Grained Ge Films on TiN

Abstract

Germanium films were deposited by low-pressure chemical vapor deposition on TiN substrates using a Si seeding technique. By depositing a self-limiting Si film on TiN via SiH 4 decomposition at 380°C, a continuous, amorphous Ge film could subsequently be deposited by GeH 4 decomposition at 320°C. Amorphous Ge films were crystallized by thermal annealing at ജ405°C for 60 m. Polycrystalline Ge films on TiN are shown to have larger grains and fewer stacking faults when deposited amorphous and subsequently crystallized, compared to films polycrystalline as-deposited.

Control of Lateral Dimension in Metal-Catalyzed Germanium Nanowire Growth: Usage of Carbon Sheath

“…The rough and thick NW surface probes the highly active Ge decomposition at high temperatures, as seen in Figure 3e. 45 The repeated "on-off" process of C 2 H 2 gas flow causes GeNWs to grow with elliptic fragments of which the positions and numbers of the fragments can be controlled during the in situ CVD process (Supporting Information, Figure S5). These results show that the catalytic carbon sheath simultaneously formed during the NW growth can efficiently block the unintentional Ge vapor deposition on NW surface even at a high-temperature process, due to the chemical repulsive interaction of the carbon sheath with Ge adatoms.…”

“…When C 2 H 2 gas flow was stopped for 30 s under the same conditions, the NW morphology was dramatically changed due to the uncatalyzed lateral growth (dot line). The rough and thick NW surface probes the highly active Ge decomposition at high temperatures, as seen in Figure e . The repeated “on-off” process of C 2 H 2 gas flow causes GeNWs to grow with elliptic fragments of which the positions and numbers of the fragments can be controlled during the in situ CVD process (Supporting Information, Figure S5).…”