Investigation of Substrate Noise Coupling and Isolation Characteristics for a 0.35UM HV CMOS Technology

This paper presents the characterization of substrate noise coupling and the isolation capability of ohmic substrate contacts in a HV CMOS technology. Layout variations of contact sizes, distances, and several p+ guard structures are subject of this research. Metal shielded DUT fixtures have been developed to improve the reliability and accuracy of the measurements. All test cases are fabricated with a 0.35 mum HV CMOS technology (Vmax <= 120 V). This process features high resistive native substrate (20 Ohm.cm) together with a 0.5 Ohm.cm pwell. The modeling section describes the distributed substrate "resistor" and the DUT fixture behavior.