Other

Bsd Medical Corporation

Pyrexar Medical Inc.

Los Alamos National Security, LLC

Bds Medical Corporation

Mark J Hagmann

Paul F Turner

Thomas L Youd

John F Sutton

Jason Lynn Elsworth

Dmitry A Yarotski

In order to meet the needs of the semi-conductor industry as it requires finer lithography nodes, a method of feedback control for scanning probe microscopy generates a microwave frequency comb of harmonics in a tunneling junction by irradiating the junction with mode-locked pulses of electromagnetic radiation. Utilizing power measurements within one or more harmonics, the tip-sample distance in the tunneling junction may be regulated for maximum efficiency and avoid tip crash when used with resistive samples. Optionally, no DC bias is required to use the method. Utilization of this method contributes to true sub-nanometer resolution of images of carrier distribution in resistive samples such as semi-conductors.

Frequency comb feedback control for scanning probe microscopy

The superimposition of a periodic potential wave to the tip movement control or the bias supply of an STM, in which a microwave frequency comb is generated in its tunneling junction, may be used to reduce or eliminate artifacts or other noise generated from outside the tunneling junction.

Method of carrier profiling in semiconductors

A radio frequency annular phased array hyperthermia system providing a relatively small heated focal zone in a relatively large tissue mass includes a plurality of radio frequency energy applicators in at least one ring adapted to surround the relatively large tissue mass. A bolus having a dielectric constant is positioned between the energy applicators and the tissue mass. The energy applicators operate at a frequency high enough to create the relatively small heated focal zone. The spacing between adjacent applicators in the at least one ring is less than a critical distance and spacing between adjacent rings when the at least one ring is a plurality of side by side rings is less than a critical distance with such critical distances being interdependent on the frequency of the energy radiated, the dielectric constant of the bolus, the size of the bolus, and the size of the relatively large tissue mass.

Apparatus and method for creating small focus deep hyperthermia in tissue

A mode-locked laser injects pulses of minority carriers into a semiconductor sample. A microwave frequency comb is then generated by the currents formed in the movement of majority carriers native to the semiconductor and the injected minority carriers. These carriers move to cause dielectric relaxation in the sample, which can be used to determine carrier density within the sample. Measurements require close proximity of transmitter and receiver contacts with the sample and may profile a semi-conductor with a resolution of approximately 0.2 nm.

Method of carrier profiling utilizing dielectric relaxation

A semiconductor carrier profiling method utilizes a scanning tunneling microscope and shielded probe with an attached spectrum analyzer to measure power loss of a microwave frequency comb generated in a tunneling junction. From this power loss and by utilizing an equivalent circuit or other model, spreading resistance may be determined and carrier density from the spreading resistance. The methodology is non-destructive of the sample and allows scanning across the surface of the sample. By not being destructive, additional analysis methods, like deconvolution, are available for use.

Apparatus and algorithm for carrier profiling in scanning frequency comb microscopy

A control methodology for scanning tunneling microscopy is disclosed. Instead of utilizing Integral-based control systems, the methodology utilizes a dual-control algorithm to direct relative advancement of a STM tip towards a sample. A piezo actuator and stepper motor advances an STM tip towards a sample at a given distance until measuring a current greater than or equal to a desired setpoint current. Readings of the contemporaneous step are analyzed to direct the system to change continue or change direction and also determine the size of each step. In simulations where Proportion and/or Integral control methodology was added to the algorithm the stability of the feedback control is decreased. The present methodology accounts for temperature variances in the environment and also appears to clean and protect the tip electrode, prolonging its useful life.

Electrode control methodology for a scanning tunneling microscope

A microwave frequency comb (MFC) is produced when a mode-locked ultrafast laser is focused on the tunneling junction of a scanning tunneling microscope (STM). The MFC consists of hundreds of measureable harmonics at integer multiples of the pulse repetition frequency of the laser, which are superimposed on the DC tunneling current. In Scanning Frequency Comb Microscopy (SFCM) the tip and/or sample electrode of the STM is moved vertically and laterally so that the power in the MFC may be measured at one or more locations on the surface of the sample and, from the power, carrier density, and other characteristics, of the sample may be calculated. SFCM is non-destructive of the sample. While many systems are possible to practice SFCM, a preferred apparatus is disclosed.

Scanning frequency comb microscopy (SFCM) for carrier profiling in semiconductors

The accuracy of tissue heating in a body when using a phased array hyperthermia system can be improved by using, in conjunction with the hyperthermia system, a program for predicting heating patterns within the tissue based upon a selected E-field value at each of the antenna energy feedpoints. The hyperthermia system includes circuitry necessary to provide information for calculating the complete EM field at each of the antenna feedpoints during treatment, and such calculated actual feedpoint EM fields are feed to the program to be used in place of the otherwise program generated e-fields in predicting the heating pattern produced by the hyperthermia system during treatment. Further initial operating parameters of the hyperthermia system can be set to produce calculated actual EM fields at the antenna feedpoints which approximate the E-field values used by the program in pretreatment optimizing of the heating pattern.

Tissue heating prediction using feedpoint EM field determination

Heat treatment is applied to tissue in need of such treatment which is surrounded by tissue not in need of such treatment, by positioning a deposit within the surrounding tissue adjacent the tissue in need of treatment. The dielectric constant and/or the conductivity of the deposit is greater than that of the surrounding tissue. A radio frequency antenna or antenna array directs a radio frequency signal at a selected frequency into the deposit. The deposit has a diameter within a range of about 0.5 times to about 0.16 times the wavelength of the radio frequency signal within the surrounding tissue. The deposit is heated, at least partially through resonant heating, to a temperature greater than the surrounding tissue to apply heat treatment to the tissue in need of treatment. The deposit may take the form of a balloon of a Mammosite&#xae; type device to provide hyperthermia treatment in conjunction with radiation treatment of a breast after a lumpectomy.

Apparatus and method for selectively heating a deposit in fatty tissue in a body

A method for coupling high-frequency energy, in particular for microwave circuits, to a nanoscale junction involves placing a bias-T outside of the tip and sample circuits of a scanning probe microscope and connecting a portion of a sample of analyzed semi-conductor through an outer shielding layer of coaxial cable so as to complete a circuit with minimal involvement of the sample. The bias-T branches into high and low-frequency circuits, both of which are completed and, at least the high-frequency circuit, does not rely on grounding of implements or other structure to accomplish said completion.

Method and means for coupling high-frequency energy to and/or from the nanoscale junction of an electrically-conductive tip with a semiconductor

Apparatus for generating a microwave frequency comb (MFC) in the DC tunneling current of a scanning tunneling microscope (STM) by fast optical rectification, caused by nonlinearity of the DC current vs. voltage curve for the tunneling junction, of regularly-spaced, short pulses of optical radiation from a focused mode-locked, ultrafast laser, directed onto the tunneling junction, is described. Application of the MFC to high resolution dopant profiling in semiconductors is simulated. Application of the MFC to other measurements is described.

Generation of a frequency comb and applications thereof

Field emission devices utilizing capacitive ballasting are described with possible uses in industry. The preferred device utilizes opposing electrodes, each with a dielectric layer and a plurality of conductive islands which serve to exchange electrons, generating an oscillatory current. Ideally these islands are dome-shaped and made of a refractory metal such as tungsten of molybdenum. Through proper use and selection of materials, electrical fields with densities of 10A/mare capable of being generated.

Symmetric field emission devices using distributed capacitive ballasting with multiple emitters to obtain large emitted currents at high frequencies

An apparatus and method for providing hyperthermia treatments to a protruding body portion having fatty tissue surrounding a deposit in the protruding body portion is disclosed. The apparatus includes a cavity for receiving the protruding body portion. A radio frequency antenna array is used to direct a radio frequency signal at a selected frequency into the protruding body portion such as a breast so that the radio frequency signal will have a selected wavelength in the breast to create a circularly polarized radio frequency electromagnetic field to selectively heat the deposit to a temperature greater than the surrounding fatty tissue through resonant heating within the deposit when a diameter of the deposit is within a range of about 0.5 times to 0.16 times the wavelength of the radio frequency signal within the fatty mammary tissue.

A hyperthermia treatment system for heating a selected region within a target body that includes a power source and a plurality of electromagnetic applicators that are in electrical communication with the power source and arranged in a surrounding array around a focal region to concentrate their combined radiation output onto the focal region. The treatment system also includes a support mechanism that is adapted to support a target body within the surrounding array of applicators, and a positioning mechanism adapted to move the support mechanism and align the selected region within the target body with the focal region. Furthermore, the positioning mechanism is adapted to compensate for movement of the focal region in response to an interaction between the combined radiation output and the target body.

Deep heating hyperthermia using phased arrays and patient positioning

A system and corresponding method for irradiating a target with electromagnetic radiation to produce a heated region. The system comprises a coupling device operable to couple electromagnetic radiation from a magnetic resonance imaging system. A plurality of energy radiator applicators are connected to the coupling device to receive electromagnetic radiation energy from the coupling device. Each of the radiator applicators is operable to emit a radio frequency heating signal using the electromagnetic radiation energy from the coupling device. A bolus filled with a dielectric fluid is positioned within the inner area of the MRI system. The bolus is operable to receive the radio frequency heating signals from the plurality of energy radiator applicators and direct the radio frequency heating signals into a section of the body to produce a heated region within the body.

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Salt Lake City, UT, United States of America

Mark J Hagmann