Circuit and method for a digital process monitor

摘要

A circuit and method for a digital process monitor is disclosed. Circuits for comparing a current or voltage to a current or voltage corresponding to a device having process dependent circuit characteristics are disclosed, having converters for converting current or voltage measurements proportional to the process dependent circuit characteristic to a digital signal and outputting the digital signal for monitoring. The process dependent circuit characteristics may be selected from transistor threshold voltage, transistor saturation current, and temperature dependent quantities. Calibration is performed using digital techniques such as digital filtering and digital signal processing. The digital process monitor circuit may be formed as a scribe line circuit for wafer characterization or placed in an integrated circuit die as a macro. The process monitor circuit may be accessed using probe pads or scan test circuitry. Methods for monitoring process dependent characteristics using digital outputs are disclosed.