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James S. Im, New York US

James S. Im, New York, NY US

Patent application numberDescriptionPublished
20090001523Systems and Methods for Processing a Film, and Thin Films - In some embodiments, a method of processing a film is provided, the method comprising defining a plurality of spaced-apart regions to be pre-crystallized within the film, the film being disposed on a substrate and capable of laser-induced melting; generating a laser beam having a fluence that is selected to form a mixture of solid and liquid in the film and where a fraction of the film is molten throughout its thickness in an irradiated region; positioning the film relative to the laser beam in preparation for at least partially pre-crystallizing a first region of said plurality of spaced-apart regions; directing the laser beam onto a moving at least partially reflective optical element in the path of the laser beam, the moving optical element redirecting the beam so as to scan a first portion of the first region with the beam in a first direction at a first velocity, wherein the first velocity is selected such that the beam irradiates and forms the mixture of solid and liquid in the first portion of the first region, wherein said first portion of the first region upon cooling forms crystalline grains having predominantly the same crystallographic orientation in at least a single direction; and crystallizing at least the first portion of the first region using laser-induced melting.01-01-2009
20090045181SYSTEMS AND METHODS FOR PROCESSING THIN FILMS - The present disclosure is directed to methods and systems for processing a thin film samples. In an exemplary method, semiconductor thin films are loaded onto two different loading fixtures, laser beam pulses generated by a laser source system are split into first laser beam pulses and second laser beam pulses, the thin film loaded on one loading fixture is irradiated with the first laser beam pulses to induce crystallization while the thin film loaded on the other loading fixture is irradiated with the second laser beam pulses. In a preferred embodiment, at least a portion of the thin film that is loaded on the first loading fixture is irradiated while at least a portion of the thin film that is loaded on the second loading fixture is also being irradiated. In an exemplary embodiment, the laser source system includes first and second laser sources and an integrator that combines the laser beam pulses generated by the first and second laser sources to form combined laser beam pulses. In certain exemplary embodiments, the methods and system further utilize additional loading fixtures for processing additional thin film samples. In such methods and systems, the irradiation of thin film samples loaded on some of the loading fixtures can be performed while thin film samples are being loaded onto the remaining loading fixtures. In certain exemplary methods and systems, the crystallization processing of the semiconductor thin film samples can consist of a sequential lateral solidification (SLS) process.02-19-2009
20090130795SYSTEMS AND METHODS FOR PREPARATION OF EPITAXIALLY TEXTURED THICK FILMS - The disclosed subject matter relates to the use of laser crystallization of thin films to create epitaxially textured crystalline thick films. In one or more embodiments, a method for preparing a thick crystalline film includes providing a film for crystallization on a substrate, wherein at least a portion of the substrate is substantially transparent to laser irradiation, said film including a seed layer having a predominant surface crystallographic orientation; and a top layer disposed above the seed layer; irradiating the film from the back side of the substrate using a pulsed laser to melt a first portion of the top layer at an interface with the seed layer while a second portion of the top layer remains solid; and re-solidifying the first portion of the top layer to form a crystalline laser epitaxial with the seed layer thereby releasing heat to melt an adjacent portion of the top layer.05-21-2009
20090137105SYSTEMS AND METHODS FOR PREPARING EPITAXIALLY TEXTURED POLYCRYSTALLINE FILMS - The disclosed subject matter relates to systems and methods for preparing epitaxially textured polycrystalline films. In one or more embodiments, the method for making a textured thin film includes providing a precursor film on a substrate, the film includes crystal grains having a surface texture and a non-uniform degree of texture throughout the thickness of the film, wherein at least a portion of the this substrate is transparent to laser irradiation; and irradiating the textured precursor film through the substrate using a pulsed laser crystallization technique at least partially melt the film wherein the irradiated film crystallizes upon cooling to form crystal grains having a uniform degree of texture.05-28-2009
20090140173METHOD AND APPARATUS FOR PROCESSING THIN METAL LAYERS - A method and apparatus for processing a thin metal layer on a substrate to control the grain size, grain shape, and grain boundary location and orientation in the metal layer by irradiating the metal layer with a first excimer laser pulse having an intensity pattern defined by a mask to have shadow regions and beamlets. Each region of the metal layer overlapped by a beamlet is melted throughout its entire thickness, and each region of the metal layer overlapped by a shadow region remains at least partially unmelted. Each at least partially unmelted region adjoins adjacent melted regions. After irradiation by the first excimer laser pulse, the melted regions of the metal layer are permitted to resolidify. During resolidification, the at least partially unmelted regions seed growth of grains in adjoining melted regions to produce larger grains. After completion of resolidification of the melted regions following irradiation by the first excimer laser pulse, the metal layer is irradiated by a second excimer laser pulse having a shifted intensity pattern so that the shadow regions overlap regions of the metal layer having fewer and larger grains. Each region of the metal layer overlapped by one of the shifted beamlets is melted throughout its entire thickness, while each region of the metal layer overlapped by one of the shifted shadow regions remains at least partially unmelted. During resolidification of the melted regions after irradiation by the second radiation beam pulse, the larger grains in the at least partially unmelted regions seed growth of even larger grains in adjoining melted regions. The irradiation, resolidification and re-irradiation of the metal layer may be repeated, as needed, until a desired grain structure is obtained in the metal layer.06-04-2009
20090173948UNIFORM LARGE-GRAINED AND GRAIN BOUNDARY LOCATION MANIPULATED POLYCRYSTALLINE THIN FILM SEMICONDUCTORS FORMED USING SEQUENTIAL LATERAL SOLIDIFICATION AND DEVICES FORMED THEREON - Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed. In one preferred arrangement, a method includes the steps of generating a sequence of excimer laser pulses, controllably modulating each excimer laser pulse in the sequence to a predetermined fluence, homoginizing each modulated laser pulse in the sequence in a predetermined plane, masking portions of each homoginized fluence controlled laser pulse in the sequence with a two dimensional pattern of slits to generate a sequence of fluence controlled pulses of line patterned beamlets, each slit in the pattern of slits being sufficiently narrow to prevent inducement of significant nucleation in region of a silicon thin film sample irradiated by a beamlet corresponding to the slit, irradiating an amorphous silicon thin film sample with the sequence of fluence controlled slit patterned beamlets to effect melting of portions thereof corresponding to each fluence controlled patterned beamlet pulse in the sequence of pulses of patterned beamlets, and controllably sequentially translating a relative position of the sample with respect to each of the fluence controlled pulse of slit patterned beamlets to thereby process the amorphous silicon thin film sample into a single or polycrystalline silicon thin film.07-09-2009
20090189164UNIFORM LARGE-GRAINED AND GRAIN BOUNDARY LOCATION MANIPULATED POLYCRYSTALLINE THIN FILM SEMICONDUCTORS FORMED USING SEQUENTIAL LATERAL SOLIDIFICATION AND DEVICES FORMED THEREON - Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed. In one preferred arrangement, a method includes the steps of generating a sequence of excimer laser pulses, controllably modulating each excimer laser pulse in the sequence to a predetermined fluence, homoginizing each modulated laser pulse in the sequence in a predetermined plane, masking portions of each homoginized fluence controlled laser pulse in the sequence with a two dimensional pattern of slits to generate a sequence of fluence controlled pulses of line patterned beamlets, each slit in the pattern of slits being sufficiently narrow to prevent inducement of significant nucleation in region of a silicon thin film sample irradiated by a beamlet corresponding to the slit, irradiating an amorphous silicon thin film sample with the sequence of fluence controlled slit patterned beamlets to effect melting of portions thereof corresponding to each fluence controlled patterned beamlet pulse in the sequence of pulses of patterned beamlets, and controllably sequentially translating a relative position of the sample with respect to each of the fluence controlled pulse of slit patterned beamlets to thereby process the amorphous silicon thin film sample into a single or polycrystalline silicon thin film.07-30-2009
20090218577HIGH THROUGHPUT CRYSTALLIZATION OF THIN FILMS - Under one aspect, a method of processing a film includes defining a plurality of spaced-apart regions to be crystallized within a film, the film being disposed on a substrate and capable of laser-induced melting; generating a sequence of laser pulses having a fluence that is sufficient to melt the film throughout its thickness in an irradiated region, each pulse forming a line beam having a length and a width; continuously scanning the film in a first scan with a sequence of laser pulses at a velocity selected such that each pulse irradiates and melts a first portion of a corresponding spaced-apart region, wherein the first portion upon cooling forms one or more laterally grown crystals; and continuously scanning the film in a second time with a sequence of laser pulses at a velocity selected such that each pulse irradiates and melts a second portion of a corresponding spaced-apart region, wherein the first and second portions in each spaced-apart region partially overlap, and wherein the second portion upon cooling forms one or more laterally grown crystals that are extended relative to the one or more laterally grown crystals of the first portion.09-03-2009
20090242805SYSTEMS AND METHODS FOR UNIFORM SEQUENTIAL LATERAL SOLIDIFICATION OF THIN FILMS USING HIGH FREQUENCY LASERS - Under one aspect, a method for processing a thin film includes generating a first set of shaped beamlets from a first laser beam pulse, each of the beamlets of the first set of beamlets having a length defining the y-direction, a width defining the x-direction, and a fluence that is sufficient to substantially melt a film throughout its thickness in an irradiated film region and further being spaced in the x-direction from adjacent beamlets of the first set of beamlets by gaps; irradiating a first region of the film with the first set of shaped beamlets to form a first set of molten zones which laterally crystallize upon cooling to form a first set of crystallized regions including crystal grains that are substantially parallel to the x-direction and having a length and width substantially the same as the length and width of each of the shaped beamlets and being separated from adjacent crystallized regions by gaps substantially the same as the gaps separating the shaped beamlets; generating a second set of shaped beamlets from a second laser beam pulse, each beamlet of the second set of beamlets having a length, width, fluence, and spacing that is substantially the same as the length, width, fluence, and spacing of each beamlet of the first set of beamlets; and continuously scanning the film so as to irradiate a second region of the film with the second set of shaped beamlets to form a second set of molten zones that are displaced in the x-direction from the first set of crystallized regions, wherein at least one molten zone of the second set of molten zones partially overlaps at least one crystallized region of the first set of crystallized regions and crystallizes upon cooling to form elongations of crystals in said at least one crystallized region.10-01-2009
20090309104SYSTEMS AND METHODS FOR CREATING CRYSTALLOGRAPHIC-ORIENTATION CONTROLLED poly-SILICON FILMS - In accordance with one aspect, the present invention provides a method for providing polycrystalline films having a controlled microstructure as well as a crystallographic texture. The methods provide elongated grains or single-crystal islands of a specified crystallographic orientation. In particular, a method of processing a film on a substrate includes generating a textured film having crystal grains oriented predominantly in one preferred crystallographic orientation; and then generating a microstructure using sequential lateral solidification crystallization that provides a location-controlled growth of the grains orientated in the preferred crystallographic orientation.12-17-2009
20100032586Uniform Large-Grained And Grain Boundary Location Manipulated Polycrystalline Thin Film Semiconductors Formed Using Sequential Lateral Solidification And Devices Formed Thereon - Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed. In one preferred arrangement, a method includes the steps of generating a sequence of excimer laser pulses, controllably modulating each excimer laser pulse in the sequence to a predetermined fluence, homogenizing each modulated laser pulse in the sequence in a predetermined plane, masking portions of each homogenized fluence controlled laser pulse in the sequence with a two dimensional pattern of slits to generate a sequence of fluence controlled pulses of line patterned beamlets, each slit in the pattern of slits being sufficiently narrow to prevent inducement of significant nucleation in region of a silicon thin film sample irradiated by a beamlet corresponding to the slit, irradiating an amorphous silicon thin film sample with the sequence of fluence controlled slit patterned beamlets to effect melting of portions thereof corresponding to each fluence controlled patterned beamlet pulse in the sequence of pulses of patterned beamlets, and controllably sequentially translating a relative position of the sample with respect to each of the fluence controlled pulse of slit patterned beamlets to thereby process the amorphous silicon thin film sample into a single or polycrystalline silicon thin film.02-11-2010
20100065853PROCESS AND SYSTEM FOR LASER CRYSTALLIZATION PROCESSING OF FILM REGIONS ON A SUBSTRATE TO MINIMIZE EDGE AREAS, AND STRUCTURE OF SUCH FILM REGIONS - A process and system for processing a thin film sample are provided. In particular, a beam generator can be controlled to emit at least one beam pulse. The beam pulse is then masked to produce at least one masked beam pulse, which is used to irradiate at least one portion of the thin film sample. With the at least one masked beam pulse, the portion of the film sample is irradiated with sufficient intensity for such portion to later crystallize. This portion of the film sample is allowed to crystallize so as to be composed of a first area and a second area. Upon the crystallization thereof, the first area includes a first set of grains, and the second area includes a second set of grains whose at least one characteristic is different from at least one characteristic of the second set of grains. The first area surrounds the second area, and is configured to allow an active region of a thin-film transistor (“TFT”) to be provided at a distance therefrom.03-18-2010
20100099273ENHANCING THE WIDTH OF POLYCRYSTALLINE GRAINS WITH MASK - A system, method and masking arrangement are provided of enhancing the width of polycrystalline grains produced using sequential lateral solidification using a modified mask pattern is disclosed. One exemplary mask pattern employs rows of diamond or circular shaped areas in order to control the width of the grain perpendicular to the direction of primary crystallization.04-22-2010
20100197147SINGLE-SHOT SEMICONDUCTOR PROCESSING SYSTEM AND METHOD HAVING VARIOUS IRRADIATION PATTERNS - High throughput systems and processes for recrystallizing thin film semiconductors that have been deposited at low temperatures on a substrate are provided. A thin film semiconductor workpiece is irradiated with a laser beam to melt and recrystallize target areas of the surface exposed to the laser beam. The laser beam is shaped into one or more beamlets using patterning masks. The mask patterns have suitable dimensions and orientations to pattern the laser beam radiation so that the areas targeted by the beamlets have dimensions and orientations that are conducive to semiconductor recrystallization. The workpiece is mechanically translated along linear paths relative to the laser beam to process the entire surface of the work piece at high speeds. Position sensitive triggering of a laser can be used generate laser beam pulses to melt and recrystallize semiconductor material at precise locations on the surface of the workpiece while it is translated on a motorized stage.08-05-2010
20100233888Method And System For Providing A Continuous Motion Sequential Lateral Solidification For Reducing Or Eliminating Artifacts In Edge Regions, And A Mask For Facilitating Such Artifact Reduction/Elimination - An arrangement, process and mask for implementing single-scan continuous motion sequential lateral solidification of a thin film provided on a sample such that artifacts formed at the edges of the beamlets irradiating the thin film are significantly reduced. According to this invention, the edge areas of the previously irradiated and resolidified areas which likely have artifacts provided therein are overlapped by the subsequent beamlets. In this manner, the edge areas of the previously resolidified irradiated areas and artifacts therein are completely melted throughout their thickness. At least the subsequent beamlets are shaped such that the grains of the previously irradiated and resolidified areas which border the edge areas melted by the subsequent beamlets grow into these resolidifying edges areas so as to substantially reduce or eliminate the artifacts.09-16-2010
20100270557METHODS OF PRODUCING HIGH UNIFORMITY IN THIN FILM TRANSISTOR DEVICES FABRICATED ON LATERALLY CRYSTALLIZED THIN FILMS - Methods of producing high uniformity in thin film transistor devices fabricated on laterally crystallized thin films are described. A thin film transistor (TFT) includes a channel area disposed in a crystalline substrate, which has grain boundaries that are approximately parallel with each other and are spaced apart with approximately equal spacings. The shape of the channel area includes a non-equiangular polygon that has two opposing side edges that are oriented substantially perpendicular to the grain boundaries. The polygon further has an upper edge and a lower edge. At least a portion of each of the upper and lower edges is oriented at a tilt angle with respect to the grain boundaries. The tilt angles are selected such that the number of grain boundaries covered by the polygon is independent of the location of the channel area within the crystalline substrate.10-28-2010
20110101368FLASH LAMP ANNEALING CRYSTALLIZATION FOR LARGE AREA THIN FILMS - The disclosed subject matter generally relates a method of irradiating a large area thin film with a pulsed light source. In some embodiments, the disclosed subject matter particularly relates to utilizing flash lamp annealing in combination with patterning techniques for making thin film devices. The flash lamp annealing can trigger lateral growth crystallization or explosive crystallization in large area thin films. In some embodiments, capping layers or proximity masks can be used in conjunction with the flash lamp annealing.05-05-2011
20110108108FLASH LIGHT ANNEALING FOR THIN FILMS - A method of making a crystalline film includes providing a film comprising seed grains of a selected crystallographic surface orientation on a substrate; irradiating the film using a pulsed light source to provide pulsed melting of the film under conditions that provide a mixed liquid/solid phase and allowing the mixed solid/liquid phase to solidify under conditions that provide a textured polycrystalline layer having the selected surface orientation. One or more irradiation treatments may be used. The film is suitable for use in solar cells.05-12-2011
20110108843COLLECTIONS OF LATERALLY CRYSTALLIZED SEMICONDUCTOR ISLANDS FOR USE IN THIN FILM TRANSISTORS - Collections of laterally crystallized semiconductor islands for use in thin film transistors and systems and methods for making same are described. A display device includes a plurality of thin film transistors (TFTs) on a substrate, such that the TFTs are spaced apart from each other and each include a channel region that has a crystalline microstructure and a direction along which a channel current flows. The channel region of each of the TFTs contains a crystallographic grain that spans the length of that channel region along its channel direction. Each crystallographic grain in the channel region of each of the TFTs is physically disconnected from and crystallographically uncorrelated with each crystallographic grain in the channel region of each adjacent TFT.05-12-2011
20110121306Systems and Methods for Non-Periodic Pulse Sequential Lateral Solidification - The disclosed systems and method for non-periodic pulse sequential lateral solidification relate to processing a thin film. The method for processing a thin film, while advancing a thin film in a selected direction, includes irradiating a first region of the thin film with a first laser pulse and a second laser pulse and irradiating a second region of the thin film with a third laser pulse and a fourth laser pulse, wherein the time interval between the first laser pulse and the second laser pulse is less than half the time interval between the first laser pulse and the third laser pulse. In some embodiments, each pulse provides a shaped beam and has a fluence that is sufficient to melt the thin film throughout its thickness to form molten zones that laterally crystallize upon cooling. In some embodiments, the first and second regions are adjacent to each other. In some embodiments, the first and second regions are spaced a distance apart.05-26-2011

Patent applications by James S. Im, New York, NY US