Eric Dean Wagner

US Patent:

52457966, Sep 21, 1993

Filed:

Apr 2, 1992

Appl. No.:

7/862044

Inventors:

Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

B24B 53007

US Classification:

51283R

Abstract:

Slurry in a slurry polisher is ultrasonically agitated during polishing to dislodge embedded debris and grit from the polishing pad and thereby improve the uniformity of material removal, lengthen the life of the pad and avoid scratches and defects on the surface being polished. The method is particularly useful for applications in which slurry polishing is used for planarizing deposited layers on semiconductor wafers where non-uniformities caused by such embedded material can affect process yields. Apparatus is disclosed for applying ultrasonic energy to the slurry so that such energy is focussed on the pad.

US Patent:

57449651, Apr 28, 1998

Filed:

Sep 17, 1996

Appl. No.:

8/714908

Inventors:

Gabriel Lorimer Miller - Westfield NJ
Eric Richard Wagner - South Plainfield NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G01R 3104

US Classification:

324538

Abstract:

A system for monitoring the integrity of electrical connections includes a transformer with its primary coupled across a dual split contact arrangement and the secondary coupled to both an energy source and a monitoring circuit. When the contact condition is made the secondary impedance reaches a given value which results in a low output indicated by the monitoring circuit. The energy source is preferably a radio frequency oscillator driving the transformer secondary, which is also connected to a monitoring circuit. Preferably, the output from a current reference circuit, coupled to the secondary of the transformer, is coupled to the energy source circuit and the monitoring circuit so as to produce a given output in the monitoring circuit when the contact condition is made.

US Patent:

50721798, Dec 10, 1991

Filed:

Jun 12, 1990

Appl. No.:

7/536824

Inventors:

Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

G01B 730
G01B 714
G08C 1906

US Classification:

32420716

Abstract:

Position indicating apparatus that allows position detection with windings provided on only one of two members and an output signal in which the position of one of the members relative to the other member is directly encoded in the phase of the output signal. A first member has a plurality of spaced ferromagnetic protuberances. A second member, movable with respect to the first member, contains at least first, second and third poles located in proximity to the protuberances and spans 360 spatial degrees. Each pole contains a winding with one terminal of each winding connected to a common point. The windings are driven at a fundamental carrier frequency with individual signals of equal amplitude but different temporal phases that span 360 temporal degrees. Circuit means detect the phase of the resulting carrier signal at the common point, which phase is linearly representative of position. Embodiments are disclosed for dimensional linear, one dimensional rotary, two dimensional planar and two dimensional cylindrical motion.

US Patent:

57011338, Dec 23, 1997

Filed:

Oct 13, 1994

Appl. No.:

8/322886

Inventors:

Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G09G 300

US Classification:

345 46

Abstract:

A circuit for driving light emitting diodes with a precise amount of current in response to an input pulse is disclosed. The input pulse drives a transistor into saturation, and the collector current of this transistor is increased in value through the use of two cascaded multiplying current mirrors. The second current mirror directly drives the light emitting diodes.

US Patent:

50850709, Feb 4, 1992

Filed:

Feb 7, 1990

Appl. No.:

7/476865

Inventors:

Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

G01B 528

US Classification:

73105

Abstract:

A force balancing method and apparatus detects small changes in force or pressure. An LC tuned circuit having a capacitor with at least one movable plate senses force or pressure changes. Deviations in the phase of the response of the tuned circuit are compared to the phase of a driving reference oscillator to generate an error signal. The error signal is used to control the oscillator to increase or decrease its output amplitude for driving the tuned circuit. As a result the electrostatic force across the capacitor plates tends to change in such a way as to precisely balance the effect of external force or pressure changes. The system therefore operates in a force-balance mode and in such a way as to provide a high sensitivity together with a precisely controlled stiffness. This system is particularly applicable to high sensitivity microphones, micro-topography, and atomic force microscopy.

US Patent:

50814214, Jan 14, 1992

Filed:

May 1, 1990

Appl. No.:

7/517106

Inventors:

Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

G01R 2726

US Classification:

324671

Abstract:

This invention provides an in situ monitoring technique and apparatus for chemical/mechanical planarization end point detection in the process of fabricating semiconductor or optical devices. Fabrication of semiconductor or optical devices often requires smooth planar surfaces, either on the surface of a wafer being processed or at some intermediate stage e. g. a surface of an interleaved layer. The detection in the present invention is accomplished by means of capacitively measuring the thickness of a dielectric layer on a conductive substrate. The measurement involves the dielectric layer, a flat electrode structure and a liquid interfacing the article and the electrode structure. Polishing slurry acts as the interfacing liquid. The electrode structure includes a measuring electrode, an insulator surrounding the measuring electrode, a guard electrode and another insulator surrounding the guard electrode.

US Patent:

54805295, Jan 2, 1996

Filed:

Nov 16, 1994

Appl. No.:

8/340515

Inventors:

Ratnaji R. Kola - Berkeley Heights NJ
Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

AT&T Corp. - Murray Hill NJ

International Classification:

C23C 1434

US Classification:

20429803

Abstract:

X-ray masks are typically made by depositing and patterning a layer of heavy metal on a thin supporting membrane. The metal layer must have a relatively low stress to prevent stress-induced deformation of the pattern. Tungsten films having excellent stress characteristics are produced by employing a continuously operating capacitance-based measurement technique to allow adjustment of the deposition conditions in rapid response to changes in stress of the film being deposited.

US Patent:

54811040, Jan 2, 1996

Filed:

Sep 30, 1994

Appl. No.:

8/316587

Inventors:

Gabriel L. Miller - Westfield NJ
Eric R. Wagner - South Plainfield NJ

Assignee:

AT&T Corp. - Murray Hill NJ

International Classification:

H01J 4014

US Classification:

250214C

Abstract:

A photodetector circuit is disclosed which can extract a carrier frequency signal from an optical beam. A photodiode is back-biased by a voltage supply, and the capacitance of the photodiode is dependent on the value of its back-bias potential. The photodiode is connected in parallel resonance with an inductor, and the parallel resonant combination is connected to the input of an inverting amplifier having a feedback capacitor. This feedback capacitor causes a capacitive component to appear in the input impedance of the amplifier which combines with the photodiode capacitance and the inductor to provide a parallel resonant tank circuit. The amplifier has a change in gain versus change in power supply characteristic. By selecting the value of the feedback capacitor, changes in the capacitive component of the input impedance are equal and opposite to changes in the capacitance of the photodiode, and the resonant frequency of the tank circuit is thereby essentially unaffected by changes in the supply voltage. A resistive element is added to the feedback impedance in order to lower the Q of the tank circuit to accommodate input signals having broader bandwidth.