Patent ID: 8617313

Claim:
A system for preparing a semiconductor film for an active matrix display, the system comprising: a laser source providing laser pulses having a pulse frequency of greater than about 4 kHz and having an average power of greater than 100 W; laser optics that shape the laser beam into a line beam, the line beam having a length, a width and a length to width aspect ratio greater than 50, the shaped laser beam having a substantially uniform fluence along the length of the line beam; a stage for support a sample capable of translation in at least one direction; memory for storing a set of instructions, the instructions comprising: (a) irradiating a first region of the film with a first laser pulse to form a first molten zone, said first molten zone demonstrating a variation in width along its length to thereby define a maximum width (W max ) and a minimum width (W min ), wherein the first molten zone crystallizes upon cooling to form one or more laterally grown crystals wherein the crystals grow substantially perpendicular to the length of the line beam; (b) laterally displacing the film relative to the line beam in the direction of lateral crystal growth a distance that is greater than about one-half W max and less than W min ; and (c) irradiating a second region of the film with a second laser pulse to form a second molten zone having a shape that is substantially the same as the shape of the first molten zone, wherein the second molten zone crystallizes upon cooling to form one or more laterally grown crystals that are elongations of the one or more crystals in the first region, wherein laser optics are selected to provide W max less than 2Ã—W min .