Mismatch and flicker noise characterization of tantalum nitride thin film resistors for wireless applications

A new tantalum nitride thin film resistor (TFR) technology for application in analog and mixed signal Si-IC technologies has been characterized for mismatch and noise behavior. Due to excellent matching properties, an optimal matching methodology and algorithms had to be developed to evaluate mismatch accurately. This analysis is performed for different layout configurations and temperatures. Based on these mismatch variations, an optimum layout set has been generated for design applications. Using this set, different models have been implemented and evaluated. In contrast to the TFR, other resistors such as polysilicon are found to exhibit a much higher mismatch and flicker noise. Correlation between thin film resistor mismatch and its crystal structure is therefore being investigated. Flicker noise measured on the TFR resistor confirms this hypothesis by showing a very low level of noise similar to metal resistors.