At&t Bell Laboratories

Lucent Technologies Inc.

At&t Ipm Corp.

At&t Laboratories, Limited

Richard A Gottscho

Konstantinos P Giapis

Eray S Aydil

Po-Yen Lu

Christian A Green

Diane Lambert

Robert A Boie

Linda A Clark

Allan R Kmetz

John Robert Morris, Jr

Geoffrey R Scheller

Zhen-Hong Zhou

Jeffrey Alan Gregus

Stephen W Downey

Richard H Krukar

Joseph B Kruskal

Bryan L Preppernau

Mark A Jarnyk

Jeffrey A Gregus

The present invention is predicated on applicants' discovery that inhomogeneity in films deposited on heated heterogeneous substrates can be substantially reduced by patterning the large area metal structures. Specifically, metal structures having areas in excess of about 2 mm.sup.2 are patterned so that the metal is within 1 mm of a metal edge. Thus, for example, a normally solid chromium bonding pad on a glass substrate is conveniently made as a patterned, open grid of 1 mm chromium lines. With such patterning, a subsequently deposited layer of silicon nitride has enhanced homogeneity over a large area, including enhanced uniformity of etching rate.

Method for coating heterogeneous substrates with homogeneous layers

A unitary display and sensing device integrates liquid crystal display module elements of a liquid crystal display module for detecting input on a flat panel display screen with the capability for digitizing the detected inputs. In accordance with an illustrative embodiment of the present invention, display elements of a liquid crystal display module are modified to sense input on the display screen. An electrical signal is applied to modified display elements of the liquid crystal display module so that contact with a surface portion of the display screen produces an output signal indicative of its location. The integrated display and sensing device is active matrix addressed for finger input, but may also incorporate display systems for active pen input.

Integrated liquid crystal display and digitizer having a black matrix

Applicants have discovered that gallium arsenide surfaces can be dry passivated without heating or ion bombardment by exposing them downstream to ammonia plasma formation. Specifically, a workpiece having exposed gallium arsenide surfaces is passivated by placing the workpiece in an evacuable chamber, evacuating in the chamber, generating an ammonia plasma removed from the immediate vicinity of the workpiece, and causing the plasma products to flow downstream into contact with the workpiece. Preferably the plasma gas pressure is 0.5 to 6.0 Torr, the substrate temperature is less than 100.degree. C. and the time of exposure is in excess of 5 min. The plasma should be generated at a location sufficiently removed from the workpiece that the workpiece surface is not bombarded with ions capable of damaging the surface (more than about 10 cm) and sufficiently close to the workpiece that reactive plasma products exist in the flow (within about 30 cm). The workpiece should also not be placed within line-of-sight of the plasma to avoid radiation (UV, visible and X-ray) induced damage. The result is fast, stable, room temperature passivation, compatible with clustered dry processing techniques for integrated circuit manufacture.

Downstream ammonia plasma passivation of GaAs

A novel vapor phase Si cleaning process comprises simultaneous exposure of the Si surface to a flux of neutral atomic hydrogen and to a flux of ionized particles. The former flux is substantially derived from a plasma, typically a microwave plasma, that is spaced apart from a second plasma, typically a RF plasma, from which the ionized particles are derived. The novel method can be implemented at relatively low cost and facilitates adjustment of the ratio between the two fluxes to result in optimal removal of, e.g., native oxide from the surface.

Method of making a silicon-based device comprising surface plasma

The formation of latent images in photoresist can be monitored during exposure without spurious images by directing a pulsed beam of monochromatic light onto a region of the layer being exposed and selectively detecting the diffracted light. Peak formation in the normalized diffracted intensity versus time curve indicates optimal exposure of the resist.

Method for monitoring photoresist latent images

In accordance with the invention, a plasma generated within a plasma confinement chamber for use in manufacturing semiconductor devices is controlled by monitoring both the neutral gas pressure P and the neutral gas temperature T. The process parameters P and T are then adjusted to control P/T.sup.n. In a preferred embodiment the pressure is adjusted to maintain P/T constant by adjusting the gas flow rate or the outlet pumping speed. The result is a plasma exhibiting enhanced stability over prolonged periods of time.

Method for controlling plasma processes

Hydrogen Plasma surface passivation of III-V Semiconductors is critically dependent on exposure time and pressure because of competition between plasma passivation and damage. Proper control of pressure according to the invention yields reproducible and stable passivation. Improved passivation is obtained using high pressure hydrogen plasmas, i.e. above 1 Torr.

Hydrogen plasma passivation of GaAs

The present invention is predicted upon the discovery by applicants that is scattered light from an etched workpiece is measured over many orders of diffraction, important characteristics of the etched workpiece can be correlated with the principal component content of the intensity characteristic. In accordance with the present invention, an etched workpiece is inspected by 1) exposing the workpiece to a beam of coherent light, 2) measuring the intensity of the light scattered from the workpiece over a range of spatial frequencies corresponding to a plurality of diffraction orders, 3) determining the principal component content of the tested workpiece intensity envelope, and 4) accepting or rejecting the workpiece in accordance with whether or not the principal component content satisfies predetermined criteria. In preferred embodiments the principal components are determined in relation to a plurality of reference measurements by singular value decomposition.

Method for inspecting etched workpieces

Reactive ion plasma etching apparatus and method are based upon the discovery of enhanced uniformity of etching at low workpiece temperatures. With cooling to sufficiently low temperatures, spontaneous etching is inhibited and etching uniformity is controlled not by gas flow and pressure but rather by ion flux. As a result, one can eliminate uniformity enhancing apparatus which heretofore obstructed optical access to the workpiece, provide window means permitting optical access to a major portion of the workpiece and employ sophisticated optical monitoring techniques during the etching process.

Plasma etching apparatus and method

Gas phase processes such as plasma etching of a semiconductor substrate is monitored by utilizing the optogalvanic effect. The substrate is subjected to light and in response emits an electron current whose magnitude is representative of the composition at the surface of the substrate. The monitored current is a sensitive indication of surface contamination and of compositional changes associated with the gas phase procedure. The technique is effectively utilized in fabricating devices such as semiconductor devices.

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Maplewood, NJ, United States of America

Richard A Gottscho