As part of the continuing reduction of half-pitch line widths, the International Technology Roadmap for Semiconductors (ITRS) forecasts an increasing number of issues with electrostatic discharge (ESD) related phenomena and the need for improved electrostatic charge control in semiconductor wafer processing. This means that wafer metrology should encompass charge measurements as a routine operation. Additionally, with the increasing complexity of wafer processing, in-line measurements including surface voltage and charge detection and analysis are becoming more important. One of the instruments utilized in such measurements is a non-contacting electrostatic voltmeter (ESVM). In this paper the authors would like to introduce a new design for the ESVM probe which allows for the measurement of surface voltages with DC stability and millivolt sensitivity. The construction of the probe utilizes a gold plated sensor that is mounted on a vibrating tuning fork which is electromechanically excited by a piezoelectric driver.
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