Palo Alto Research Center Inc.

Nanogram Corporation

Uma Srinivasan

Eric J Shrader

Shivkumar Chiruvolu

Guojun Liu

Peter Kiesel

Oliver Schmidt

Michael Bassler

Scott J Limb

Stephen David White

Steven E Ready

Bernard Frey

Scott Jong Ho Limb

Robert Matusiak

Weidong Li

Robert B Lynch

Gina Elizabeth Pengra-Leung

Igor Altman

Clark Crawford

David L Hecht

John Stuart Fitch

Robert P Kowalski

Clark W Crawford

David Stephen White

The use of doped silicon nanoparticle inks and other liquid dopant sources can provide suitable dopant sources for driving dopant elements into a crystalline silicon substrate using a thermal process if a suitable cap is provided. Suitable caps include, for example, a capping slab, a cover that may or may not rest on the surface of the substrate and a cover layer. Desirable dopant profiled can be achieved. The doped nanoparticles can be delivered using a silicon ink. The residual silicon ink can be removed after the dopant drive-in or at least partially densified into a silicon material that is incorporated into the product device. The silicon doping is suitable for the introduction of dopants into crystalline silicon for the formation of solar cells.

Silicon substrates with doped surface contacts formed from doped silicon based inks and corresponding processes

Laser pyrolysis reactor designs and corresponding reactant inlet nozzles are described to provide desirable particle quenching that is particularly suitable for the synthesis of elemental silicon particles. In particular, the nozzles can have a design to encourage nucleation and quenching with inert gas based on a significant flow of inert gas surrounding the reactant precursor flow and with a large inert entrainment flow effectively surrounding the reactant precursor and quench gas flows. Improved silicon nanoparticle inks are described that has silicon nanoparticles without any surface modification with organic compounds. The silicon ink properties can be engineered for particular printing applications, such as inkjet printing, gravure printing or screen printing. Appropriate processing methods are described to provide flexibility for ink designs without surface modifying the silicon nanoparticles.

Silicon/germanium nanoparticles and inks having low metal contamination

The presently described embodiments use a printing process, e.g. a wax printing technique, to pattern a mask layer (such as a soldermask layer) of, for example, a printed circuit. Substantially all other conventional processes in developing soldermask and exposure processes can be maintained. According to the presently described embodiments, each printed circuit will have a unique pattern that matches uniform and non-uniform runout. In one form, the pattern is comprised of wax single drops having a specified gap to make the process transparent to the current industry practice. Furthermore, the single drops can be used for both large and small areas without any development time differences. In at least one form, the wax pattern and the soldermask in the gap are removed during development.

Method and system for patterning a mask layer

Silicon substrates with doped surface contacts formed from doped silicon inks and corresponding processes

Silicon/germanium nanoparticle inks, laser pyrolysis reactors for the synthesis of nanoparticles and associated methods

A patterned layer over a wafer is produced by depositing a print-patterned mask structure. Energized particles of a target material are deposited over the wafer and the print-patterned mask such that particles of said target material incident on the mask structure enter the mask structure body and minimally accumulate, if at all, on the surface of the mask structure, and otherwise the particles of target material accumulate as a generally uniform layer over the wafer. The print-patterned mask structure, including particles of target material therein, is removed leaving the generally uniform layer of target material as a patterned layer over the wafer.

Method for patterning using phase-change material

High aspect ratio structures can be obtained by print-patterning masking features in feature stacks such that each feature has a lateral edge which is aligned in a plane roughly perpendicular to the plane of the substrate on which the features are formed. Due to the differential lateral spreading between features formed on a substrate and formed atop other features, the print head is indexed less than the radius of a droplet to a position where a droplet ejected by the print head forms an upper feature atop a lower feature such that the lateral edges of the upper and lower features are aligned in the plane roughly perpendicular to the plane of the substrate. Feature stacks of two or more features may provide a vertical (or re-entrant) sidewall mask for formation of high aspect ratio structures, by e.g., electroplating, etc.

Method for obtaining controlled sidewall profile in print-patterned structures

In the case of printing at high addressability, where the cell size is smaller than the spot size, an image can be decimated in a manner that will limit the large accumulation of printed material. The proper decimation of the image will depend on the spot size, the physics of drop coalescence and the addressability during printing. A simple method of using concentric decimation is disclosed herein to enable this process.

Method for decimation of images

A tunable optical cavity can be tuned by relative movement between two reflection surfaces, such as by deforming elastomer spacers connected between mirrors or other light-reflective components that include the reflection surfaces. The optical cavity structure includes an analyte region in its light-transmissive region, and presence of analyte in the analyte region affects output light when the optical cavity is tuned to a set of positions. Electrodes that cause deformation of the spacers can also be used to capacitively sense the distance between them. Control circuitry that provides tuning signals can cause continuous movement across a range of positions, allowing continuous photosensing of analyte-affected output light by a detector.

Processes for producing tunable optical cavities

A method for masking regions of photoresist in the manufacture of a soldermask for printed circuit boards is disclosed. Following application of photoresist over patterned traces on a substrate, a sheet-like thin film is applied over the photosensitive material. The thin film may adhere to the photosensitive material by way of the adhesive state of the photosensitive material or by way of an adhesive applied to the photosensitive material or the thin film or carried by the thin film. Digital mask printing may proceed on the surface of the thin film. The photosensitive material may then be exposed through the printed photomask, the thin film (with photomask) removed, and the photosensitive material developed.

Lamination for printed photomask

A method of printing spots with high spot placement accuracy using print heads with random/unevenly spaced ejector locations and coarse alignment of the multiple print heads. This is performed by accurately determining the spot positions from all the print heads using a vision system and printing at high addressability. The spot placement accuracy will be determined by the addressability as long as the ejected drop position is reproducible and other system errors are negligible.

Method of printing with high spot placement accuracy

An inhomogeneous optical cavity is tuned by changing its shape, such as by changing reflection surface positions to change tilt angle, thickness, or both. Deformable components such as elastomer spacers can be connected so that, when deformed, they change relative positions of structures with light-reflective components such as mirrors, changing cavity shape. Electrodes can cause deformation, such as electrostatically, electromagnetically, or piezoelectrically, and can also be used to measure thicknesses of the cavity. The cavity can be tuned, for example, across a continuous spectrum, to a specific wavelength band, to a shape that increases or decreases the number of modes it has, to a series of transmission ranges each suitable for a respective light source, with a modulation that allows lock-in with photosensing for greater sensitivity, and so forth. The optical cavity can be a linear variable filter fabricated on the photosensitive surface of a photosensing component such as a photosensor array or a position-sensitive detector.

Tuning optical cavities

A method of jet-printing smooth micro-scale features is presented. The desired feature prior to being printed is masked by various decimation filters and the decimation is performed at various pitches. The subsequently printed image is then scanned and analyzed to determine the roughness of the lines. The optimum decimation pitch is determined by the feature that exhibits the least amount of droplet spreading and has the lowest edge roughness. The optimum decimation pitch may also be calculated from the material properties and the dynamics of fluids.

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Mountain View, CA, United States of America

Uma Srinivasan