Investigation and application of vertical NPN devices for RF ESD protection in BiCMOS technology

BiCMOS technologies have been used to implement the radio-frequency (RF) integrated circuits (ICs) due to the advantages of low noise, low power consumption, high drive, and high speed. The electrostatic discharge (ESD) is one of the important reliability issues of IC. When the ESD events happen, the ESD protection devices must be turned on immediately to protect the ICs, including the RF ICs in BiCMOS technologies. In this work, the vertical NPN (VNPN) devices in 0.18 μm silicon-germanium (SiGe) BiCMOS technology with base-emitter shorted and resistor trigger approaches are investigated. In component-level, using transmission-line-pulsing (TLP) and ESD simulator test the I–V characteristics and human-body-model (HBM) robustness of the VNPN devices, respectively. In system-level, using ESD gun tests the system-level ESD robustness. The ESD protection of VNPN devices are further applied to a 2.4 GHz low-noise amplifier (LNA). After attaching the VNPN devices to LNA, the RF characteristics are not degraded while the ESD robustness can be much improved.