Xerox Corporation

Tzu-Chin Chuang

Jackson H Ho

Robert R Allen, Deceased

Ronald T Fulks

Michael G Hack

Richard H Bruce

Russel A Martin

Louis D Silverstein

Alan G Lewis

William D Turner

Thomas G Fiske

Malcolm J Thompson

William W Yao

Hugo L Steemers

Susan M Stuber

A conductive line in a thin-film structure such as an AMLCD array includes molybdenum and chromium so that it can be processed in a manner similar to chromium but has a greater conductivity than chromium due to the molybdenum. The conductive line can be produced by physical vapor deposition of a layer of a molybdenum-chromium (MoCr) alloy, which can then be masked and etched using photolithographic techniques in a manner similar to chromium. Proportions between 15 and 85 atomic percent of molybdenum can be processed more easily than pure molybdenum and are more conductive than pure chromium. Lines with between 40 and 60 atomic percent molybdenum can be used with a margin of error. To produce a tapered conductive line, sublayers of MoCr alloys with different etch rates can be produced and etched.

Thin-film structure with conductive molybdenum-chromium line

A feature in a thin-film structure such as an AMLCD array has an edge with a tapered sidewall profile, reducing step coverage problems. The feature can be produced by producing a layer in which local etch rates vary in the thickness direction of the layer. The layer can then be etched to produce the feature with the tapered sidewall profile. The layer can be produced by physical vapor deposition. The layer can, for example, includes sublayers with different etch rates, either due to different atomic proportions of constituents or due to different etchants. Or local etch rates can vary continuously as a result of changing deposition conditions. Differences in etch rates or differences in etchant mixtures can be used to obtain a desired angle of elevation.

Thin-film structure with tapered feature

The present invention is a novel multilayered structure comprising alternating layers of a base metal and a metal selected from a group of barrier metals. The base metal, in any given layer, is deposited to a thickness less than its critical thickness--a thickness beyond which hillocks are more likely to form for a given temperature. Between each such layer of base metal, a layer of barrier metal is interposed. The intervening layer of barrier metal acts to suppress the formation of hillocks in the base metal.

Hillock-free multilayer metal lines for high performance thin film

A thin-film structure on an insulating substrate includes an array of binary control units with an area of at least 90 cm.sup.2 and a density of at least 60 binary control units per cm. One implementation has an area of approximately 510 cm.sup.2, a diagonal of approximately 33 cm, and a total of approximately 6.3 million binary control units. Each binary control unit has a lead for receiving a unit drive signal, to which it responds by causing presentation of a segment of images presented by the array. Each binary control unit can present a segment with either a first color having a maximum intensity or a second color having a minimum intensity. Each binary control unit's unit drive signal causes the binary control unit to present its first and second colors. The substrate can be glass. Each binary control unit can include an amorphous silicon thin-film transistor (TFT) and a storage capacitor. Each binary control unit can be square. The thin-film structure can be used in an active matrix liquid crystal display (AMLCD), monochrome or, with an appropriate filter, color.

Thin-film structure with dense array of binary control units for

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Saratoga, CA, United States of America

Tzu-Chin Chuang