University of Houston System

Vanderbilt University

Other

John Charles Wolfe

Paul Ruchhoeft

Wei-Chuan Shih

James Richard Wasson

Gopathy Purushothaman

Mufaddal Gheewala

John Neal Randall

Barry Craver

Ivan L Berry, Iii

Wong S Ho

Jose Leonel Torres Bucardo

Sandeep V Pendharkar

Darian L Licon

Yat-lung R Chau

Ronald J Lucas

Wong-sik S Ho

Wanda Zagozdzon-Wosik

Ahmed M El-Masry

Fu-On Fong

David P Stumbo

Yat-Lung Chau

An optrode may provide a cylindrical substrate with two or more electrodes deposited on said cylindrical substrate. The cylindrical substrate and electrodes may be coated by an insulating layer with openings or vias over certain portions of the electrodes that may provide a contact for the neural probe or may be utilized to connect lead lines. Manufacturing of an optrode may utilize a jig that secures a cylindrical substrate coated by a conductive material and a resist. A first mask may be positioned in an opening provided by the jig, and the cylindrical substrate may expose ions or neutral particles to define one or more electrode patterns. After regions of the resist and conductive material are removed to form the electrodes, a second mask may be utilized to define via regions in which portions of the electrodes are exposed and uncoated by an insulating layer.

Integrated thin-film optrode

An optrode may provide a cylindrical substrate two or more electrodes deposited said cylindrical substrate. The cylindrical substrate and electrodes may be coated by an insulating layer with openings or vias over certain portions of the electrodes that may provide a contact for the neural probe or may be utilized to connect lead lines. Manufacturing of an optrode may utilize a jig that secures a cylindrical substrate coated by a conductive material and a resist. A first mask may be positioned in an opening provided by the jig, and the cylindrical substrate may be exposed ions or neutral particles to define one or more electrode patterns. After regions of the resist and conductive material are removed to form the electrodes, a second mask may be utilized to define vias regions in which portions of the electrodes are exposed and uncoated by an insulating layer.

Method of fabricating a probe

Various embodiments disclose devices and methods for fabricating microporous particulate filters with regularly spaced pores wherein sheet membrane substrates are exposed to energetic particle radiation through a mask and the damaged regions removed in a suitable developer. The required depth of field is achieved by using energetic particles to minimize diffraction and an energetic particle source with suitably small diameter.

Device and method for manufacturing a particulate filter with regularly spaced micropores

A neural probe includes a probe, wherein a tip of the probe is tapered; an insulating layer covering the probe, and one or more metallic traces, wherein the metallic traces are provide along the length of the probe. The probe also includes one or more contacts provided on the tip of the probe, wherein each of the one or more metallic traces terminates at the one or more contacts, and the one or more contacts provide an array of nanosized metallic pillars. The neural probe may also incorporate a lightguide. The lightguide may include an insulating layer providing a first cladding layer on the probe, a core layer provided on top of the first cladding layer, wherein the metallic traces and contacts are provided in the core layer with a core material, and a second cladding layer provided on top of the core layer.

Method for manufacturing a multimodal neural probe

Various embodiments disclose devices and methods for fabricating microporous particulate filters with regularly space pores wherein sheet membrane substrates are exposed to energetic particle radiation through a mask and the damaged regions removed in a suitable developer. The required depth of field is achieved by using energetic particles to minimize diffraction and an energetic particle source with suitably small diameter.

The present inventors have developed an accurate method for forming a plurality of images on a substrate. The present method provides an improved pattern replication technique that provides submicron resolution, for example 20 nm or less, especially 10 nm or less. The method may involve moving a structured beam of energetic radiation across a target substrate. The motion of an image of the template mask on the substrate is achieved by tilting a mask and substrate assembly relative to the axis of the incident beam. The technique does not require high precision motion of the template mask relative to the target substrate. The energetic radiation may comprise energetic particles. The technique is insensitive to particle energy and can be applied to uncharged, neutral particles.

Method for translating a structured beam of energetic particles across a substrate in template mask lithography

An energetic neutral particle lithographic apparatus is disclosed for replicating sub-micron and nanoscale patterns including a source producing a beam of energetic neutral particles, comprising atoms or molecules, by charge transfer scattering of energetic ions from the molecules of a gas, a mask member having open stencil windows in a supporting membrane, an energetic neutral particle protective layer on the membrane, and a reproduction member consisting of an energetic neutral particle-sensitive layer between a substrate and the mask for absorbing energetic neutral particles in a pattern created by the mask.

Energetic neutral particle lithographic apparatus and process

For producing an exposure pattern on a curved, in particular concave substrate field of a substrate which comprises a layer of resist material sensitive to exposure to an energetic radiation, in a pattern transfer system a wide, substantially parallel beam of said energetic radiation is produced, and by means of said beam a planar mask having a structure pattern, namely, a set of transparent windows to form a structured beam, is illuminated and the structure pattern is imaged onto the substrate by means of the structured beam, producing a pattern image, namely, a spatial distribution of irradiation over the substrate. The direction of incidence of said beam onto the mask is varied through a sequence of inclinations with respect to the normal axis to the mask, the sequence of inclinations being adapted to merge those exposure pattern components which result from neighboring windows of the structure pattern, the exposure with respect to the sequence of inclinations superposing into a spatial distribution of exposure dose on the substrate, said distribution exceeding the specific minimum exposure dose of said resist material within only one or more regions of the substrate field, said region(s) forming the exposure pattern. The center of curvature of the substrate field is positioned to align with the pattern center on the mask. The windows of the structure pattern are arranged in a manner that along each radius from the pattern center, the radial spacing of said windows decreases with increasing radius from the pattern center; preferably, the windows have uniform area.

Lithographic patterning of curved substrates

For lithographic patterning a plurality of identical structures ( ) onto a target substrate ( ), a template mask ( ) is produced which bears a template structure pattern comprising a plurality of identical template structures each consisting of a set of at least one structure element (C) of circular shape. Starting from a primary mask ( ) bearing a primary structure pattern consisting of at least one structure element having a circular shape, the production of the template mask is done in at least one lithographic mask structuring step (b, c) wherein in each mask structuring step by means of a broad beam ( ) of energetic radiation the mask is illuminated and a structure pattern on the mask ( ) is imaged onto an intermediate substrate ( ); in these mask structuring steps the pattern image imaged from the structure pattern is moved over the intermediate substrate to a number of different locations. From the intermediate substrate ( ) thus patterned another mask ( ) having a structure pattern corresponding to the pattern image is produced, respectively. The mask produced from the last of said mask structuring steps is the template mask ( ). By means of the template mask ( ) a target substrate ( ) is patterned in a final lithographic patterning step, the pattern image thus produced comprising a plurality of identical target structures ( ).

Template mask lithography utilizing structured beam

A method for producing a carbon film on a substrate, comprising the steps of (a) depositing a carbon layer of a predetermined thickness onto the substrate, e.g. using off-axis sputtering, the carbon layer having predominantly graphitic or amorphous structure, and (b) treating the carbon layer by means of an radio-frequency discharge in a helium atmosphere wherein the substrate is held at a negative dc bias voltage of a preselected value, where the thickness of the carbon layer deposited in step a) is chosen not greater than the longitudinal stop range of the helium ions corresponding to the bias voltage used in step b). After producing a first carbon layer of a predetermined thickness, a next carbon layer is likewise produced upon the first carbon layer and the procedure can be repeated until the total thickness of the layers attains a desired final thickness.

Process for producing a carbon film on a substrate

A method for depositing carbon films on membranes used in masks for X-ray or corpuscular projection, e.g. electron or ion beam, lithography is proposed in which sputtering is used and the membranes serving as sputter substrates are positioned in the off-axis configuration relative to the sputter targets. The carbon films thus produced have a compressive stress of the order of 10 MPa or below. For modifying the properties of carbon films after deposition, e.g. the deactivation of chemically reactive sites or stabilization of stress, ion bombardment with helium ions can be employed. This method anticipates changes in the film due to initial irradiation and serves to reach a plateau in which the stress varies only a little, i.e. within about 1 MPa or less.

Method for depositing a carbon film on a membrane

An RF diode reactive ion etching (RIE) method and apparatus (20) include an evacuable reaction chamber (22) in which an anode electrode (76) and cathode electrode (30)are spaced-apart facing each other and defining a gap (78) between the electrodes. A substrate (40) to be etched is placed in thermal contact with the cathode. A magnet (70) behind the anode provides a magnetic field which is characterized by lines-of-force (80) extending continuously through the gap from one of the electrodes to the other. To etch the substrate the reaction chamber is evacuated, an etchant-gas is admitted into the gap at a predetermined low pressure, a plasma (79) including ions of the etchant gas is generated by applying RF power to the electrodes. The substrate is etched by etchant gas ions attracted from the plasma toward the substrate by a negative self-bias potential established on the cathode.

Magnetically enhanced radio frequency reactive ion etching method and

The present invention is, in part, a new process for dopant diffusion, both p-type (e.g., B) and n-type (e.g., P, As), into silicon wafers, using rapid thermal processing (RTP). It uses a surface layer of a new planar dopant as an active dopant source. Such a source is produced using either a rigid holder wafer with a spin-on dopant or CVD doped oxides deposited on its surface, or such a source is high pressure planar solid source having a surface that has been activated by dry etching or sputtering etching. Such a dopant source is placed in proximity to a processed silicon wafer in such a manner that its active surface is facing the surface of the silicon wafer during RTP. Both the silicon wafer and the dopant source are heated by lamps emitting light causing transport of dopant from the dopant source to the silicon surface. The dopant source may be produced using either silicon wafers, quartz or ceramic plates or planar solid diffusion sources which are commercially available in a form of solid discs containing compounds containing various dopant atoms (e.g., B, P, and As).

Method and apparatus for doping silicon wafers using a solid dopant

A process for depositing a compound of a metal and a reactive gas includes heating a metal target (32), in an evacuated chamber (22) to a predetermined reaction temperature. The reaction temperature is above a critical temperature which is higher than about half the melting point of the metal but below the vaporization temperature of the metal target. At this reaction temperature, the metal target reacts with the reactive gas to produce, in gaseous form, the compound or a sub-compound of the metal and the reactive gas. The gaseous compound or sub-compound is reacted with the reactive gas on a substrate (36) to form a solid layer of the compound on the substrate.

Ion assisted deposition process including reactive source gassification

The ion beam which performs the printing on the resist through the mask is also used to perform the alignment function. Alignment marks are initially provided on the wafer of a material which emits light when an ion beam impinges thereon, such as silicon dioxide. An ion mask, preferably of silicon, is then positioned over the wafer and alignment marks and ions are directed to the alignment marks through the mask. The degree of alignment is determined by the amount of light emitted by the alignment marks since more ions will strike the alignment marks with increased alignment. The emitted light is detected and +X, -X, +Y, -Y and +theta and -theta error signals are provided on a continuous basis for closed loop control of the mask relative to the wafer under proper alignment is achieved. The control is provided by scanning the emitted light from six appropriately positioned alignment marks on the wafer, comparing the intensity of the emitted light in terms of +X amd -X signals to provide an X error signal, doing the same with the Y and theta signals to provide Y and theta error signals and then digitizing each of the error signals in a digital to analog converter. The digitized signals are then applied to a central processing unit wherein they are analyzed in accordance with a predetermined program and provide signals to a motor controller. The motor controller proceeds to provide output signals to properly position the wafer in the X and Y directions as well as to rotate the mask to provide the desired alignment between the mask and wafer.

Growing community of inventors

Houston, TX, United States of America

John Charles Wolfe