Juda Leon Shohet

7116115, Oct 3, 2006

May 24, 2004

10/852058

Yogesh B. Gianchandani - Ann Arbor MI, US
Larry L. Chu - Madison WI, US
Kenichi Takahata - Ann Arbor MI, US
Ponnambalam Selvaganapathy - Freemont CA, US
Juda L. Shohet - Madison WI, US

The Regents of the University of Michigan - Ann Arbor MI
Wisconsin Alumni Research Foundation - Madison WI

G01R 27/26
G01R 31/02
G01R 31/302

324661, 324 72, 324 725, 324750

A micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate are provided. The probe apparatus includes an integrated scanning tip and a dither actuation mechanism. The actuation is achieved using a bent-beam electrothermal actuator, and the probe tip is insulated from the actuator with a wide isolation gap. The device is fabricated by a modified micro electro-discharge machining process which allows electrical isolation within the micromachined structure using an epoxy plug. The apparatus may be used to measure changes in the external surface potential of a microfluidic channel as a function of varying pH of liquid inside the channel. The apparatus also may be used to map embedded charge in a thin layer on a substrate, showing it to be suitable for monitoring microelectronics manufacturing processes.

52890104, Feb 22, 1994

Dec 8, 1992

7/987122

Juda L. Shohet - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

H01J 37317

25049221

Plasma source ion implantation is carried out within an evacuated chamber having a target, such as a semiconductor wafer, supported on a target stage, with pulses of high voltage applied to the target periodically to implant ions from a plasma into the target. The ions in the plasma are purified after formation of the plasma by passing the plasma through an ion cyclotron resonance system composed of excitation electrodes and ion collector electrodes surrounding an ion purification region, with a magnet providing a unidirectional magnetic field through the ion purification region. A radio frequency time varying electric field from the excitation electrodes drives unwanted ions having charge-to-mass ratios greater than or less than that of the desired ion species to resonance with the electric field. During resonance, the undesired ions are driven outwardly in expanding spirals until reaching the ion collector plates, where the unwanted ions are removed. The purified plasma is passed to a plasma implantation region within the chamber from which the desired ions are implanted into the target as pulses of voltage are applied to the target.

45888884, May 13, 1986

Feb 11, 1985

6/700298

Sahba Ghaderi - Madison WI
Juda L. Shohet - Madison WI
Duane P. Littlejohn - Madison WI

Nicolet Instrument Corporation - Madison WI

H01J 4938

250291

A mass spectrometer of the type wherein the sample is ionized, excited into resonance and detected within a generally homogeneous magnetic field. During detection, the magnetic field is perturbed to form magnetic mirror regions to contain the ions. Prior to detection, the ions may be contained by conventional trapping techniques or by magnetic reflection.

47391650, Apr 19, 1988

Feb 27, 1986

6/833975

Sahba Ghaderi - Madison WI
Duane P. Littlejohn - Madison WI
Juda L. Shohet - Madison WI

Nicolet Instrument Corporation - Madison WI

B01D 5944

250290

A remote ion source within an ICR mass spectrometer which provides an enhanced trapping (within an analyzer cell) of ions formed within that remote ion source. In a preferred embodiment, trapping enhancement is accomplished by means of magnetic perturbations of the magnetic field within the analyzer cell. The perturbations may be established by ferromagnetic means or electromagnetic means or by the use of permanent magnets to form a magnetic bottle. Ions formed within the remote ion source are extracted from that source by an electrostatic lens and directed toward the analyzer cell along the Z axis of the spectrometer magnetic field. Deceleration lenses, external to the analyzer cell, may be employed to further enhance the trapping capability of the analyzer cell. In some modes of operation, a ramped deceleration potential may be applied to the declaration lens for "grouping" of ions of different masses for analysis. Provision for mass selection is also made within the spectrometer disclosed herein.