Abstract: Floating wafer provided with heating elements which, by means of a controller, keep the walls of the floating wafer reactor at the desired temperature. By means of the sensors arranged in the walls, this temperate is kept substantially constant. To compensate for the temperature drop occurring during the entering of a wafer, which is caused by the absorption of warmth by the comparatively cold wafer, and to limit temperature variation in the processing area as much as possible, it is proposed to immediately supply an amount of energy to the heating elements, independently of the reaction of the sensors, during entering of the wafer.

Abstract: The temperature of a dry etch process of a semiconductor substrate in a plasma etch chamber is controlled to maintain selectivity while also providing a high etch rate by introducing one or more cooling steps into the etch process. To maintain selectivity of the etch as well as a high rate of etch, the formation of plasma is terminated prior to exceeding a predetermined maximum temperature at at least one selected location in the chamber. The temperature at the selected location is reduced prior to the resumption of plasma flow and etching. The plasma etch is then continued, and may optionally be terminated again to permit cooling, as needed, until etching has been completed.