Sub-6 GHz RF SPDT Switches Designed in an Advanced 28 nm Fully-Depleted Silicon-on-Insulator Technology with a High Resistivity Substrate

In this paper two RF switches named as 3-stack and 12-stack are studied. They are designed to have the same overall RON and built using a 28 nm FD-SOI technology atop of different substrate resistivities. A new advanced passivation technique is also used in order to boost the switches' performance. The 3-stack switch atop of standard Process of Reference (POR) substrate (similar to 15 ohm cm) shows an insertion loss 1.2 dB higher than the same switch atop of high-resistivity (>1 k ohm cm) with advanced passivation technique. Moreover, the 12-stack switch with advanced passivation technique demonstrates 2.5 dB improvement in the insertion loss compared to the same one built on a standard substrate while the isolation remains lower than 20 dB.