Abstract: An electroetching tool using scanned localized application of flowing electrolyte against a workpiece such as a large area mask having high density features for the fabrication of microelectronic components. A masked molybdenum plate is suspended in a vertical direction within a tank which functions as a reservoir for a recirculating electrobyte. The electrolyte in the reservoir is filtered and pumped to a pair of travelling cathode assemblies from which the flowing electrolyte is simultaneously applied through respective charged orifices to both sides of the workpiece. The workpiece is masked on its opposite sides with mirror imaged mask apertures having corresponding opposite-sided features in registration with each other.Each orifice through which the electrolyte is applied comprises an open groove in the surface of a block of polyvinal chloride material which groove extends in a vertical direction relative to the tank. The bottom of the groove is adjacent to a conductive plate.

Abstract: An electroetching tool using scanned localized application of flowing electrolyte against a workpiece such as a large area mask having high density features for the fabrication of microelectronic components. A masked molybdenum plate is suspended in a vertical direction within a tank which functions as a reservoir for a recirculating electrobyte. The electrolyte in the reservoir is filtered and pumped to a pair of travelling cathode assemblies from which the flowing electrolyte is simultaneously applied through respective charged orifices to both sides of the workpiece. The workpiece is masked on its opposite sides with mirror imaged mask apertures having corresponding opposite-sided features in registration with each other.Each orifice through which the electrolyte is applied comprises an open groove in the surface of a block of polyvinal chloride material which groove extends in a vertical direction relative to the tank. The bottom of the groove is adjacent to a conductive plate.

Abstract: A molybdenum etching process which reduces hazardous treatment waste is disclosed. Etchants which can be used are ferric sulfate and ferric ammonium sulfate. Waste products resulting from this etch are Fe(OH).sub.3 and CaSO.sub.4.

Abstract: Masks for microelectronics technology are fabricated by electrochemical etching. Molybdenum sheet or foil is masked with patterned photoresist on one side, and a mating, mirror-image pattern of photoresist is applied on the other side of the foil in exact registration with the first pattern. The foil is immersed in electrolyte (an aqueous solution of sodium nitrate, sodium hydroxide, thiourea, and surfactant) along with nickel anode plates held parallel to the foil surfaces 1-3 cm away. The anode plate is made slightly smaller than the mask area of the foil. When voltage is applied across the cell, the foil is etched through to form vias. The electrolyte is pumped across the surface of the foil and uniform flow velocity over the foil surface is achieved.