Abstract: A method is provided for producing trench structures having vertical, smooth side walls and straight, flat trench floors in silicon substrates. The reactive ion etching is implemented in a triode single-wafer plate reactor upon use of an etching mask preferably composed of SiO.sub.2, and with an etching gas atmosphere exclusively composed of chlorine, being implemented at a low-pressure. Compared to known ion etching processes, the method provides acceptable etching rates with a carbon-free, simple etching chemistry. The method is particularly useful for producing DRAMs with cell concepts of more than 4 Mbits.

Abstract: The movable cutting unit of a dry-shaver comprises a plurality of cutters (23) and a corresponding plurality of hair-pulling blades (24) each arranged in front of one of the cutters for movement therewith relative to the shear plate or foil of the shaver, and each movable relative to the associated cutter for its hair-pulling action. Each hair-pulling blade is mounted for pivoting motion on its associated cutter.

Abstract: There is provided a shaving apparatus comprising a shear plate having hair entry apertures and a cutting unit associated with and drivable relative to the shear plate. The cutting unit comprises a cutting member having cutters extending toward the shear plate and respectively associated lead cutters movable relative to the cutters away from and toward the shear plate. The arrangement is such that each lead cutter is always maintained spaced from its associated cutter throughout their respective lengths regardless of their relative position.