EEPROM-based Charging-Effects Sensors for Plasma Etching and Ion Implantation

Abstract

Conventional studies of damage effects associated with plasma-based processes and ion implantation have focused on characterization of the damage inflicted on typical IC structures and devices. Although essential, these studies provide little insight regarding the nature and magnitudes of the driving forces behind the damage, which is essential for the design of more benign wafer processing equipment, process optimization, etc. This talk describes the design, characterization, and application of re-usable, EEPROM-transistor-based, wafer-level, sensors intended to quantify the driving forces behind the damage, and to v unipolar monitors for capturing information about transients of opposite polarities; extended range UV monitors; and structures for characterization of process environment equivalent networks needed for damage modeling. Most of the sensors incorporated on the monitor wafers employ EEPROM transistors, due to their sensitivity to electrostatic and photo-electric effects, and due to their ability to remember critical attributes of these driving forces. Individual sensors are personalized for specific tasks by additional elements attached to the EEPROM transistors, and by suitable pre-conditioning and test techniques. Experimental results from plasma etching and high-current ion implant experiments are presented to illustrate the capabilities of these (CHARM2) monitors.