摘要 |
A system detects the clearing of a dielectric at a plurality of contact sites by measuring the surface voltage of the dielectric and comparing the surface voltage to a reference voltage set to a value that relates to the cleared contact sites. Another system detects the clearing of a dielectric at a plurality of contact sites on a substrate by measuring the rate of change of a substrate current during an etch process and ending the etch process when the rate of change is approximately zero. Another system detects the clearing of a dielectric at a contact site by measuring a substrate current during an etch process and ends the etch process when the measured substrate current exceeds a predetermined value.
|