Abstract: The end point in plasma etching is detected by monitoring the optical emission from the plasma, selecting a particular optical emission line and detecting a substantial variation in the intensity of the emission. This indicates a change in material being etched and thus the completion of etching of one material, or the beginning of etching of another material. It is also applicable to removing, or etching, photoresist material.

Abstract: A continuous ribbon of moldable material is fed from a plasticizing mill through a stamping section of a molding machine and is returned to the mill as mill stock. The ribbon of moldable material is carried through the stamping section by an endless chain conveyor having prongs spaced therealong. The prongs are pressed into the ribbon as it is drawn from the plasticizing mill. Then, the ribbon is supported by trays as it is drawn along a feed path through the stamping section. The prongs are pulled from the ribbon once the ribbon has been directed by the conveyor back toward the plasticizing mill.At the stamping section, bites are taken from the edge of the ribbon by a die to provide blanks of molding stock to the molding machine. The ribbon is guided by edge guides along a transversely movable supporting tray. The chain conveyor rides in a trough adjacent the tray. By moving the tray and trough away from the stamping die, the mill may be operated continuously even with the mold shut down.