Measurement and Extraction of Specific Contact Resistivity

摘要

This paper presents a unified approach for the accurate extraction of specific contact resistivity rho(c) for ohmic contacts from measured contact resistance using the Cross Bridge Kelvin Resistor, the Contact End Resistor. Conventional 1-D models overestimate the value of rho(c) because of a parasitic due to two-dimensional current crowding around the periphery of the contact. Using 2-D simulations we have accurately modeled the current crowding effects and have extracted values of rho(c) independently on contact size and the test structure type. For each particular structure, a universal set of curves has been derived, which, given the geometry of the structure, allows accurate determination of rho(c), without the actual use of the 2-D simulator. Accurate values of rho(c) for various contact materials to N+ and P+ Si have been determined. The data confirms that in the past researchers have overestimated rho(c) and that rho(c) will not limit device performance even with submicron design rules. (Reprints)