John R Demarco

US Patent:

61952001, Feb 27, 2001

Filed:

Feb 18, 1998

Appl. No.:

9/025465

Inventors:

John Joseph DeMarco - East Brunswick NJ
Justin Boyd Judkins - Scotch Plains NJ
Paul Francis Wysocki - Flemington NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H01S 330
G02B 626
G01C 1972

US Classification:

359341

Abstract:

In accordance with the invention, a multiwavelength light source comprises a length of optical waveguide amplifier, a multiwavelength reflector for reflecting a plurality of different spectrally separated wavelengths optically coupled to one side of the amplifier and a low reflection output coupled to the other side. A broadband source is provided for passing broadband light to the multiwavelength reflector. In the preferred embodiment, the reflector is a plurality of reflective Bragg gratings, the waveguide amplifier is a length of rare-earth doped fiber (e. g. EDF) and the broadband source is the amplifier pumped to generate ASE. In operation, broadband light is transmitted to the gratings. Light of wavelength channels corresponding to the reflection wavelengths of the gratings is reflected back through the amplifier for further amplification before it arrives at the output. Optionally one or more transmission filters can be disposed between the reflector and the amplifier (or at the output) ASE source to control the relative magnitudes of the selected channels.

US Patent:

55893031, Dec 31, 1996

Filed:

Dec 30, 1994

Appl. No.:

8/366952

Inventors:

John J. DeMarco - East Brunswick NJ
Taeho Kook - Lower Macungie Township, Lehigh County PA
Robert L. Kostelak - Bernardsville NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G03F 900

US Classification:

430 5

Abstract:

An attenuating phase-shifting optical lithographic mask is fabricated, in a specific embodiment of the invention, by first depositing a uniformly thick molybdenum silicide layer on a top planar surface of quartz. The molybdenum silicide layer has a thickness sufficient for acting as an attenuating (partially transparent) layer in a phase-shifting mask. A uniformly thick chromium layer is deposited on the molybdenum silicide layer. The chromium layer has a thickness sufficient for acting as an opaque layer in the phase-shifting mask. Next, the chromium layer is patterned by dry or wet etching, while the chromium is selectively masked with a patterned resist layer. Then the molybdenum silicide is patterned by dry or wet etching, using the patterned chromium layer as a protective layer, whereby a composite layer of molybdenum silicide and chromium is formed having mutually separated composite stripes. Any remaining resist is removed. Next the top and sidewall surfaces of some, but not others, of these mutually separated stripes are coated with a second patterned resist layer.

US Patent:

56331037, May 27, 1997

Filed:

Jul 11, 1995

Appl. No.:

8/500729

Inventors:

John J. DeMarco - East Brunswick NJ
Christophe Pierrat - Boise ID

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G03F 900

US Classification:

430 5

Abstract:

A phase-shifting optical lithographic mask has a set of phase shifting features and a set of alignment marks, all having a common thickness and being made of a common material, such as chromium oxynitride, that is partially transparent to optical radiation used in an optical lithographic system. Both of these sets are located on a slab of quartz. An alignment shutter layer laterally intervenes between the alignment marks and the phase-shifting features, in order to suppress optical radiation leakage from the phase-shifting features to the alignment areas. A portion of the top surface of the alignment shutter layer and the entire top surface of the reinforced alignment marks are reinforced by an opaque layer, such as chrome. In addition, another similarly reinforced layer, a chip shutter layer, can be laterally located at an extremity of the reinforced alignment marks, in order to suppress optical radiation leakage from one chip area to another in step-and-repeat lithography.

US Patent:

55388191, Jul 23, 1996

Filed:

Apr 10, 1995

Appl. No.:

8/439040

Inventors:

John J. DeMarco - East Brunswick NJ
Robert L. Kostelak - Bernardsville NJ

Assignee:

AT&T Corp. - Murray Hill NJ

International Classification:

G03F 900

US Classification:

430 5

Abstract:

A phase-shifting optical lithographic mask is made by a method that produces a set of phase shifting features (11) located in phase-shifting areas and a set of reinforced alignment marks (13, 33) located in alignment areas of the mask. Both of these sets are located on a single slab of quartz (10). The method involves a lift-off step that results in the self-alignment of the alignment marks with respect to the phase-shifting features. All of the phase-shifting features together with all of the alignment marks are patterned during a single step, and all of them comprise a bottom layer (11) of common material and common thickness so as to be partially transparent to optical radiation used in an optical lithographic system. Typically the bottom layer is essentially chromium oxynitride. In order to suppress optical radiation leakage from the phase-shifting features to the alignment mark areas, a reinforced alignment-mark shutter layer (12, 32) is located between the reinforced alignment marks and the phase-shifting areas, and it is made simultaneously with the reinforced alignment marks.

US Patent:

52883680, Feb 22, 1994

Filed:

Mar 2, 1993

Appl. No.:

8/025714

Inventors:

John J. DeMarco - East Brunswick NJ
Christophe Pierrat - Basking Ridge NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

B44C 122
C03C 1500
C23F 100

US Classification:

156643

Abstract:

A direct-writing electron beam is used for defining features in a resist layer and hence ultimately in an underlying workpiece, such as in a phase-shifting mask substrate or a semiconductor integrated circuit wafer. The resist layer is located on a top major surface of the workpiece. In a specific embodiment, the resist layer is located underneath a protective layer of polyvinyl alcohol ("PVA"); and a grounded conductive layer, such as a conductive organic layer, is located on the protective layer. After exposing the top major surface of the resulting structure to the direct-writing electron beam, the following steps are performed: (1) a plasma etching completely removes the entire thickness of the conductive layer as well as a small fraction of the thickness of the PVA layer; (2) the PVA layer is then completely removed by dissolving it in water; (3) another plasma etching removes a small fraction of the thickness of the resist layer, including any unwanted residues; and (4) the resist layer is developed.