Charged device model electrostatic discharge protection and test methods for integrated circuits

This work focuses on methods for testing and increasing the robustness of integrated circuits (ICs) to electrostatic discharge (ESD). Specifically, this work focuses on charged device model (CDM) protection and test methods. In this work it is shown that the CDM robustness of an I/O can be increased by proper biasing of the gates during an ESD event. These gate bias networks are particularly useful because they do not add capacitance to high-speed nodes. The effectiveness of diode vs. diode-triggered silicon controlled rectifier (DTSCR) protection in high-speed I/O cells is examined. The industry standard for CDM characterization of a product is field-induced CDM (FICDM) testing of packaged ICs. However, several wafer-level CDM testers have also been introduced, including very-fast transmission line pulsing (VF-TLP) and capacitively coupled TLP (CC-TLP). This work presents three new wafer-level CDM testers. Two are modifications of existing CC-TLP and “WCDM” testers. The modified testers allow one to probe internal nodes during the stress event. The third, named “WCDM2,” is an improvement upon WCDM. The merits and drawbacks of each of these testers are examined in this work. Primarily, this work seeks to methodically answer the outstanding question of whether or not wafer-level CDM testing can replicate FICDM stress. An embeddable voltage monitor circuit is presented that is capable of recording for subsequent readout the peak voltage reached at internal nodes during ESD events. Techniques for probing internal nodes during CDM-like events are also presented. Using these and other techniques, fatal and non-fatal stress generated within two CDM test chips by the various CDM testers are compared to each other. It is shown that wafer-level testing does not replicate FICDM stress in various scenarios.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Jack, Nathan

Contributors dc:contributor

• Rosenbaum, Elyse
• Cangellaris, Andreas C.
• Schutt-Ainé, José E.
• Shanbhag, Naresh R.

• electrostatic discharge
• charged device model
• transmission line pulsing
• wafer-level CDM (WCDM)
• ESD test methods
• IC reliability
• charged device model (CDM)
• electrostatic discharge (ESD)
• field-induced CDM (FICDM)
• WCDM2
• capacitively coupled TLP (CC-TLP)
• Transmission line pulsing (TLP)
• very-fast transmission line pulsing (VF-TLP)
• integrated circuits (ICs)

Statement dc:rights

• Copyright 2012 Nathan Jack

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/30911

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/30911