Specific contact resistivity of Al-NiSi contacts using Cross Kelvin Resistor test structure chains

Abstract

Silicide contacts are used in semiconductor devices because of their relatively low sheet resistance as thin films and because they form contacts with relatively low values of specific contact resistivity leading overall to low values of contact resistance. Determining the true values of the specific contact resistivity of metal-to-silicide interfaces is a challenge that requires suitable test structures. The Cross Kelvin Resistor (CKR) structure is a commonly used test structure for the extraction of the specific contact resistance of ohmic contacts. Analysis using this structure has errors associated with it and the challenge is often in determining this error. This paper demonstrates a technique that uses several Cross Kelvin Resistor structures connected in a chain and determines the specific contact resistance of aluminium to nickel silicide contacts using extrapolation rather than determining the error. The formation of the nickel silicide films and the fabrication and testing results for the Cross Kelvin Resistor structures are presented.

Investigating extremely low resistance ohmic contacts to silicon carbide using a novel test structure

“…Specific contact resistivity (ρ c ) is an extremely important parameter, which quantifies this metal to semiconductor ohmic contact. The measurement of ρ c for ohmic contacts to semiconductor has been reported by a number of people who used transmission line model and circular transmission line model [1][2][3][4][5][6][7] .…”