Abstract: In an improved method for etching a groove n the uppermost layer of a semiconductor wafer, a conventional anisotropic etch is performed to achieve a narrow groove and an isotropic etch is performed to widen the groove at the device surface and thereby round the edges where the walls of the groove meet the surface of the wafer. During a later step of applying a protective tape to the device side of the wafer to protect it during a step of grinding the back of the wafer, the rounded edges of the groove are unlikely to cut through the adhesive layer of the tape and thereby cause particles of adhesive to remain on the wafer surface when the tape is removes.

Abstract: Amorphous or polycrystalline silicon layers are sometimes used in the metallization steps of IC processes, for example as antireflex coatings or as etching stopper layers for etching back of tungsten. A problem is that such a layer cannot be provided by CVD or LPCVD on account of the high deposition temperature which is not compatible with standard Al metallizations. Other deposition techniques, such as sputtering or plasma CVD, often lead to a lesser material quality, a longer processing time per wafer, or a worse step covering. According to the invention, the layer is provided by CVD or LPCVD at a temperature below 500° C. under the addition of Ge. The GexSi1−x layer (8) thus obtained is found to have good properties as regards step covering, optical aspects, electrical aspects, and etching aspects, and is compatible with any Al metallization (6) already present.

Abstract: A slurry for chemical-mechanical polishing comprises a high pH solution with particles of a catalyst mixed with the high pH solution for accelerating the polishing rate. The catalyst preferably is a metal selected from the group consisting of platinum, silver, palladium, copper, rhodium, nickel, and iron. The catalyst may be impregnated into a polishing pad used to apply the slurry to a surface. A CMP process for metal surfaces includes applying a slurry to a metal surface to be polished, and providing an electrical bias to the workpiece and to the slurry for controlling the polishing rate. The electrical bias is provided to dies in the workpiece by means of an electrical connection between a bias voltage source and scribe lines between adjacent dies.

Abstract: The present invention relates to single crystal silicon, in ingot or wafer form, which contains an axially symmetric region in which vacancies are the predominant intrinsic point defect and which is substantially free of agglomerated vacancy intrinsic point defects, wherein the first axially symmetric region comprises the central axis or has a width of at least about 15 mm, and a process for the preparation thereof.