Abstract: A laser device includes a light source part; an optical path adjustment part; a light distribution part that splits a laser beam into a plurality of sub-beams to a substrate; a drive part that moves the light distribution part and adjusts relative positions between the light distribution part and the substrate; a sensing part; and a control part. The control part generates an image based on a signal sensed by the sensing part and measures an image contrast of the image. The control part records and compares a plurality of image contrasts according to the position of the light distribution part to determine an optimal position of the light distribution part.

Abstract: A laser etching method include performing a first emission process by emitting a laser beam from a laser module toward a substrate fastened to a chuck in a laser etching chamber, moving a protection window between the chuck and the laser module in a first direction by a first distance after the performing the first emission process, performing a second emission process by emitting a laser beam from the laser module after the moving the protection window in the first direction by the first distance, moving the protection window in an opposite direction of the first direction by a second distance after the performing the second emission process, and performing a third emission process by emitting a laser beam from the laser module after the moving the protection window in the opposite direction of the first direction by the second distance.

Abstract: A thin film transistor includes a gate electrode formed on a substrate, a semiconductor pattern overlapped with the gate electrode, a source electrode overlapped with a first end of the semiconductor pattern and a drain electrode overlapped with a second end of the semiconductor pattern and spaced apart from the source electrode. The semiconductor pattern includes an amorphous multi-elements compound including a II B element and a VI A element or including a III A element and a V A element and having an electron mobility no less than 1.0 cm2/Vs and an amorphous phase, wherein the VI A element excludes oxygen. Thus, a driving characteristic of the thin film transistor may be improved.