摘要 |
The current density versus voltage characteristics of integrated circuit processing equipment such as a plasma etcher are determined using a passive probe including a semiconductor wafer in which one or more clusters of individual passive charge monitors are fabricated. Each monitor includes an EEPROM device having a control electrode and a floating electrode over a channel region connecting source and drain regions, a charge collecting electrode connected to the control electrode, and a current sensing resistor connecting the charge collection electrode to the substrate for developing a threshold varying voltage. By determining changes in device threshold voltage, a corresponding surface-substrate potential is determined which can be divided by the value of the current-sensing resistor to yield a current. The current can then be divided by the area of the charge collecting electrode to yield a value of the current density. A single charge flux monitor thus yields one point on the J-V characteristic curve of the monitored charging source.
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