Abstract: An electrochemical method for defect delineation in thin-film SOI or SOS wafers in which a surface of a silicon wafer is electrically connected so as to control the voltage of the surface within a specified range, the silicon wafer is then contacted with an electrolyte, and, after removing the electrolyte, defects and metal contamination in the silicon wafer are identified.

Abstract: A reproducible process for uniformly etching silicon from a series of micromechanical structures used in electrical devices and the like includes providing a micromechanical structure having a silicon layer with defined areas for removal thereon and an electrochemical cell containing an aqueous hydrofluoric acid electrolyte. The micromechanical structure is submerged in the electrochemical cell and the defined areas of the silicon layer thereon are anodically biased by passing a current through the electrochemical cell for a time period sufficient to cause the defined areas of the silicon layer to become porous. The formation of the depth of the porous silicon is regulated by controlling the amount of current passing through the electrochemical cell. The micromechanical structure is then removed from the electrochemical cell and submerged in a hydroxide solution to remove the porous silicon.

Abstract: Amorphous ternary nickel-chromium-phosphorus alloys are electrodeposited from a bath comprising a nickel salt, a chromium salt, a phosphorus source such as sodium hypophosphite, a complexing agent for the nickel ions, supporting salts to increase conductivity, and a buffering agent. The process is carried out at about room temperature and requires a current density between about 20 to 40 A/dm.sup.2.

Abstract: A process for the in-situ mining of subterranean uranium ore deposits comprising pretreating the deposits by the steps of injecting an aqueous inorganic chloride solution therein to substantially saturate the deposits and injecting an aqueous alkaline lixiviant solution therein to flush the chloride solution from the deposits. Thereafter, the pretreated deposits may be solution mined in conventional fashion such as by injecting an oxidant-containing aqueous alkaline lixiviant therein and recovering uranium-containing lixiviant solution. The inorganic chloride solution is preferably potassium chloride and the preferred lixiviants are potassium carbonate, sodium carbonate and ammonium carbonate.