A self-aligned vertical Kelvin test structure to measure contact resistivities of Al and Ti on Si

A self-aligned vertical Kelvin test resistor structure, which not only eliminates the horizontal current crowding but also avoids the misalignment error, is proposed and used to measure p_c of Al and Ti on Si. For the Al(1%Si)/n⁺-Si contact system, a specific contact resistivity of 1×10^-7 Ω-cm² has been measured. For the TiSi₂ contacts, the TiSi₂(direct-reaction)/n⁺-Si contact offers a lower p_c than that of the coevaporated TiSi ₂/n⁺-Si contact, and p_c does not change even after the contacts are annealed to 900°C