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The film stress of Ni films deposited at near-ambient temperatures from sulfamate electrolytes was investigated. The particulate filtering of the electrolyte, a routine industrial practice, becomes an important deposition parameter at lower bath temperatures. At 28°C, elevated tensile film stress develops at low current densities ͑Ͻ10 mA/cm 2 ͒ if the electrolyte is filtered. Filtering at higher current densities has a negligible effect on film stress. A similar though less pronounced trend is observed at 32°C. Sulfate-based Ni plating baths display similar film stress sensitivity to filtering, suggesting that this is a general effect for Ni electrodeposition. It is shown that filtering does not significantly change either the current efficiency or the pH near the surface during deposition. The observed changes in film stress are thus attributed not to adsorbed hydrogen but instead to the effects of filtering on the formation and concentration of polyborate species due to the decreased solubility of boric acid at near-ambient temperatures.

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Novel technology is presented which allows the rapid replication of electroforming plastic micromolds. This technique incorporates microscreens into hot embossing or injection molding processes to produce sacri®cial molds with conducting bases and insulating sidewalls. Both contiguous and non-contiguous features can be electroformed from these molds. Process parameters including the microscreen geometry and the use of multiple porous metal inserts are discussed.

Gold, used as an X-ray absorber for lithography and as a structural or conducting material in microsystems, was deposited from a commercially available sulfite electrolyte. The effects of current type and an arsenic additive on the gold microstructure and residual stress were studied. Using a simple bent strip method, good agreement with literature stress values determined via other methods was obtained. Without arsenic, residual stresses are tensile (ϳ50 MPa) regardless of current type. With 25 ppm arsenic, the stress is compressive for direct current ͑ca. Ϫ30 MPa), with pulsed current reducing the stress to ϽϪ5 MPa compressive; this has been noted previously with thallium as an additive. The addition of arsenic does not appreciably change the film grain size but does lower the twin density and modify texture. Pores were observed in all the gold films, but were larger and less concentrated for films produced with arsenic; for the case of direct current with arsenic, the pores were concentrated at the grain boundaries. Consistencies in the microstructural observations and thin film stress theories are discussed.