Patent ID: 9543225
Date: 2017-01-10
CPC Classifications: H01L

Claim:
1. A plasma processing system, comprising: a plasma processing chamber having an exterior, an interior region equipped with an electrostatic chuck assembly for receiving a semiconductor wafer, and a viewport providing visual access from the exterior to at least a portion of the semiconductor wafer when present on the electrostatic chuck assembly, wherein the viewport is disposed on a side wall of the plasma processing chamber such that the viewport is below a transformer-coupled plasma (TCP) window defined on the side wall of the chamber that is above the surface of the semiconductor wafer, the viewport providing an unobstructed view of the portion of the surface of the semiconductor wafer; a camera mounted to the viewport of the plasma processing chamber on the exterior, the camera configured to take sequential images of a pattern emerging on the portion of the semiconductor wafer during an etching operation; an image processor coupled to the camera, the image processor being in communication with pattern recognition logic to match the images transmitted by the camera at regular intervals, to a reference pattern and to generate a signal identifying an endpoint to the etch operation, upon detection of a match; and a host computer in communication with the image processor and the plasma processing chamber, the host computer configured to receive the signal identifying the end point that causes the etch operation to stop.