Abstract
In this work, we show that an excessive lattice heating problem can occur in the diode electrostatic discharge (ESD) protection device connected to a VDD bus in the popular diode input protection scheme, which is favorably used in CMOS RF ICs. To figure out the reason for the excessive lattice heating, we construct an equivalent circuit for input human-body model (HBM) test environment of a CMOS chip equipped with the diode protection circuit, and execute mixed-mode transient simulations utilizing a 2-D device simulator. We analyze the simulation results in detail to show out that a parasitic pnp bipolar transistor action relating nearby p+-substrate contacts is responsible for the excessive lattice heating in the diode protection device, which has never been focused before anywhere.
Highlights
CMOS chips are vulnerable to electrostatic discharge (ESD) due to the thin gate oxides used, and protection devices are required at input pads
By analyzing the simulation results, we show that severe lattice heating in the diode device can occur due to a trigger of parasitic pnp bipolar transistor action
We encountered with an excessive lattice heating problem in the diode ESD protection device connected to a VDD bus in the popular diode input protection scheme, which is favorably used in CMOS RF ICs
Summary
CMOS chips are vulnerable to electrostatic discharge (ESD) due to the thin gate oxides used, and protection devices are required at input pads. In the diode input protection scheme, it is essential to include a VDD-VSS clamp NMOS device in an input pad structure to provide discharge paths for all possible human-body model (HBM) test modes. In RF ICs, to reduce parasitics added to input nodes, it is important to minimize the diode size by optimizing device structure. In this work, based on 2-D mixed-mode (device and circuit) simulation, we figure out that the mechanism leading to diode protection device failure is mostly related to a trigger of parasitic pnp bipolar transistor involving the p-type substrate contacts.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
