1. A method of monitoring the clean, rinse and dry processes for the manufacture of micro devices, comprising: providing an electro-chemical residue sensor (ECRS) comprising a micro feature formed in or on a dielectric film and first and second conductive electrodes adapted to receive an ac signal to measure the impedance of the micro feature; calibrating the ECRS in known solutions for each of cleaning, rinsing and drying processes; processing the ECRS through a sequence of cleaning, rinsing and drying processes; and using the ECRS to monitor the impedance of the ECRS's micro feature as representative of residual contamination of similar device micro features on production wafers as the ECRS is transferred through the processes.