Contact Resistance and Adhesion Characteristics of Oxidized Tantalum Nitride Mirors

摘要

Oxidation of tantalum nitride resistor films used in hybrid microcircuits is an unavoidable phenomenon known to affect interfacial properties between resistor and conductor layers. At room temperature, oxide thickness increases with time at an unknown rate; therefore, a three-day limitation between Ta sub 2 N and Cr/Au conductor deposition is presently specified for hybrid microcircuits. The effects of Ta sub 2 N aging on resistor-conductor contact resistance and conductor bondability were evaluated. Accelerated aging produced oxide layers of various thicknesses which were then correlated to contact resistance. Analytical data and calculations indicate that a 25 percent increase in contact resistance would occur by exposing the Ta sub 2 N to air for approximately three years at room temperature and pressure prior to metallization. However, little or no change in bondability would be expected. (ERA citation 01:020093)