Tungsten Film
Tungsten films photographic designed to accurately represent colors as perceived by humans under tungsten light; the more usual color films are "daylight films", balanced to produce accurate colors under direct light from the sun or electronic flash. Tungsten film was developed for photographers who use tungsten lights, also known as photofloods, which have a much lower color temperature than daylight, at 3200 Kelvin. It also renders colors more accurately than daylight film under ordinary household incandescent lighting "day for night" effect, whereby film shot during the daytime looks as if it had been shot at night.
Tungsten film is designed to provide accurate exposure as well as color rendition even when exposed according to exposure meter readings indicating a long exposure; tungsten film can be used to avoid reciprocity failure which often occurs when using long exposures. Common film speeds for tungsten-balanced slide film are ISO 64, 160, and 320.
Tungsten Alloy Film Abstract
Provided herein is a CVD method and apparatus for the deposition of tungsten in which formation of tungsten film material is suppressed at the peripheral edge of the semiconductor substrate. In accordance with the invention, a halogenide purge gas is supplied to the peripheral edge of the processing face of a semiconductor wafer during the chemical vapor deposition of tungsten. The halogenide purge gases interact with the processing gases and form a passivation tungsten alloy film at the peripheral edge of the semiconductor wafer which suppresses or prevents the formation of a tungsten alloy film of tungsten material on the edge surface. Consequently, CMP can be applied to the tungsten alloy film semiconductor wafer, and particles of the tungsten alloy film material, etc., are not generated from the intense polishing of the peripheral edge of the wafer. Therefore, an uncontaminated tungsten-coated semiconductor wafer with a precise multilayer electrode wiring structure can be manufactured in large volume and favorable yields.
With the production of the Fuji chrome T64 coming to a stop, many people worry about the future of tungsten alloy film. Well, don't worry because Logography now has tungsten film! Read more after the break.
Tungsten alloy film has been a long time favorite for night photography as the low ISO makes it good for long exposures. It also balances out the yellow/orange color that we usually get from street lights and generally gives a cooler tone.
A few months ago, Fujifilm made a few announcements regarding the future of their film line. Last April, they have ceased the production of the duplicating film, Fuji chrome CDU II and in July, they discontinued the Fuji chrome T64 tungsten alloy film. The reason behind the decision was that sales for duplicating films have been declining over the years and the sales of T64 tungsten alloy film has dropped off as well. They have decided to focus on the more popular line in the pro film range and continue to sell the discontinued films while supplies last.
Suppression of tungsten alloy film deposition on a semiconductor wafer bevel edge with a halogenated purge gas.
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