Mismatch characterization of a high precision resistor array test structure

In this paper we describe a 2x (2xn) pad resistor array test structure. The structure can also be used for analog CMOS, bipolar, capacitor arrays. It provides a flexible and convenient way to study devices in an array. We will focus on various matching properties of the precision thin film resistors, specifically, between any one of the resistors with the average of the whole array, between two resistors (neighbor and far away pair), and between resistor combinations in the array. Both random and systematic mismatch properties are studied. We illustrate key factors for resistor matching from both process and layout perspectives. The principles, analyses and main conclusions apply to other active and passive devices as well. The array layout can be copied directly from and into a circuit design.