An infrared television camera (20) monitors the etching of a substrate (26) in-situ in an etch chamber (24). Temporal and spatial resolution of IR emissions is obtained by monitoring the top surface of the substrate (26) in two-dimensions throughout the course of the etching process. Anomalies in temperature detected on the top surface of the substrate (26) can indicate defects in the substrate (26) itself or in the operation of the etching apparatus. Process feedback control is achieved by adjusting various parameters of the etching apparatus (i.e., gas-pressure, flow pattern, magnetic field, coolant flow to electrode, or the like) to compensate for etching anomalies. Etch uniformity and etch endpoint monitoring is achieved by monitoring the IR emissions resulting from exothermic reaction of the film being etched. IR emissions decline at the end of an exothermic etch reaction. Particulate matter which might otherwise harm the substrate (26) can be identified in the gas-phase with a second IR television camera (34) which images the region above the substrate (26). Particulate matter appears as localized "hot spots" within the gas plasma, and the identification of particulate matter allows corrective measures to be taken.