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1994
Conference Paper
Titel
Influence of tester parasitics on "charged devive model"-failure thresholds
Abstract
The weak correlation betweeen Charged Device Model (CDM) testers may be attributed to calibration problems and the complex system interaction between tester and device for ultra-fast high-current transients. This thesis is derived on the basis of one carefully studied device type and two CDMtesters by means of experiment and simulation. The CDM-metrology for static and transient stress parameters was developed. Robotic and socketed CDM failure thresholds as well as signatures were analyzed for the lum-CMOS-inputs. CDM-relevant parts were extracted from package and layout to develop a "First order" CDM circuit model of the device. Simulated results were verified by physical failure signatures. We tried to emulate the influence of characteristic elements of socketed testers on failure thresholds and signatures by adding background capacitances and transmission lines to a robotic system. These background capacitances increased failure voltage and current thresholds due to a parasitic SCR- action. The failure signatures remained the same. Again CDMdegraded devices failed minor electrical overstress, such as 20V-HBM emphasizing the need for CDM-tests in addition to HBM.
Konferenz
Language
English