摘要:
A system for preparing a semiconductor film, the system including: a laser source; optics to form a line beam, a stage to support a sample capable of translation; memory for storing a set of instructions, the instructions including irradiating a first region of the film with a first laser pulse to form a first molten zone, said first molten zone having a maximum width (Wmax) and a minimum width (Wmin), wherein the first molten zone crystallizes to form laterally grown crystals; laterally moving the film in the direction of lateral growth a distance greater than about one-half Wmax and less than Wmin; and irradiating a second region of the film with a second laser pulse to form a second molten zone, wherein the second molten zone crystallizes to form laterally grown crystals that are elongations of the crystals in the first region, wherein laser optics provide Wmax less than 2×Wmin.
摘要:
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 pulses. The beam pulses have suitable dimensions and orientations to pattern the laser beam radiation so that the areas targeted by the beam have dimensions and orientations that are conductive to semiconductor recrystallization. The workpiece is mechanically translated along linear paths relative to the laser beam to process the entire surface of the workpiece at high speeds. Position sensitive triggering of a laser can be used to 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.
摘要:
The disclosure relates to methods and systems for single-scan line-scan crystallization using superimposed scanning elements. In one aspect, the method includes generating a plurality of laser beam pulses from a pulsed laser source, wherein each laser beam pulse has a fluence selected to melt the thin film and, upon cooling, induce crystallization in the thin film; directing a first laser beam pulse onto a thin film using a first beam path; advancing the thin film at a constant first scan velocity in a first direction; and deflecting a second laser beam pulse from the first beam path to a second beam path using an optical scanning element such that the deflection results in the film experiencing a second scan velocity of the laser beam pulses relative to the thin film, wherein the second scan velocity is less than the first scan velocity.
摘要:
In one aspect, the present disclosure relates to a method of processing a thin film including, while advancing a thin film in a first selected direction, irradiating a first region of the thin film with a first laser pulse and a second laser pulse, each laser pulse providing a shaped beam and having a fluence that is sufficient to partially melt the thin film and the first region re-solidifying and crystallizing to form a first crystallized region, and irradiating a second region of the thin film with a third laser pulse and a fourth laser pulse, each pulse providing a shaped beam and having a fluence that is sufficient to partially melt the thin film and the second region re-solidifying and crystallizing to form a second crystallized region, 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.
摘要:
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.
摘要:
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.
摘要:
The present invention is directed to systems and methods for irradiating regions of a thin film sample(s) with laser beam pulses having different energy beam characteristics that are generated and delivered via different optical paths. An exemplary method includes generating laser beam pulses having energy beam characteristics, directing a first pulse onto a first optical path, modulating the pulse's energy beam characteristics, and irradiating at least a portion of a first region of the thin film with the pulse to induce crystallization of the portion of the first region. The method also includes directing a second pulse onto a second optical path, modulating the pulse's energy beam characteristics so as to be different from the energy beam characteristics of the first pulse, and irradiating at least a portion of a second region of the thin film with the second pulse to induce crystallization of the portion of the second region.
摘要:
Methods and devices are described relating to an electronic device positioned at a known location in a crystalline film including a crystalline semiconductor comprising a region of location controlled crystalline grains; a device located in the crystalline semiconductor film at a location that is defined relative to the location of the location controlled crystalline grains. The method includes irradiating at least a portion of a semiconductor film using two or more overlapping irradiation steps, wherein each irradiation step at least partially melts and laterally crystallizes a lithographically defined region the film to obtain a region of laterally grown crystalline grains having at least one long grain boundary that is perpendicular to the lateral growth length; identifying the location of at least one long grain boundary; and manufacturing an electronic device in the semiconductor film at a location that is defined relative to the location of the long grain boundary.
摘要:
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.
摘要:
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.