Atomically Flat Low-Resistive Germanide Contacts Formed by Laser Thermal Anneal

In this paper, state-of-the-art laser thermal annealing is used to form germanide contacts on n-doped Ge and is systematically compared with results generated by conventional rapid thermal annealing. Surface topography, interface quality, crystal structure, and material stoichiometry are explored for both annealing techniques. For electrical characterization, specific contact resistivity and thermal stability are extracted. It is shown that laser thermal annealing can produce a uniform contact with a remarkably smooth substrate interface with specific contact resistivity two to three orders of magnitude lower than the equivalent rapid thermal annealing case. It is shown that a specific contact resistivity of $2.84\times 10^{-7}~\Omega\cdot{\rm cm}^{2}$ is achieved for optimized laser thermal anneal energy density conditions.