Reducing substrate noise coupling in a 3D-PICS integrated passive device by localized P+ guard rings

This paper presents an original concept of a P+ guard ring realized in a 300¼m depth High Resistivity Silicon Substrate (HRS) in order to reduce the substrate noise coupling in a 3D-PICS Integrated Passive Device technology. Guard rings have been designed to be a reliable and efficient protection against noise signals propagation. Case study presented in this work illustrates its significant role. In this paper, a 3D-PICS IPD test chip was studied as a first passive part prototype of a System-In-Package chip in combination with RF transceiver operating in the ISM band (863-870 MHz). Various configurations of the passive chip layout (including implementation of guard rings) have been characterized by Direct Power Injection. 3D-PICS electrical performances deduced from two-ports S-parameters are reported, as well as the guard rings efficiency measurements extracted from these S-parameters. Coupling isolation performances of the new integrated PICS components are found satisfactory.