US Patent 7276317 Laser mask and method of crystallization using the same

A laser mask and method of crystallization using the same that can produce a polycrystalline silicon thin film having uniform crystallization characteristics. According to the present invention, a method of crystallization using a laser mask having a reference pattern in a first block and the reverse pattern of the reference pattern in a second block includes providing a substrate having a silicon thin film; positioning the first block of the laser mask over a portion of the silicon film and irradiating a first laser beam through the first block; and moving either the laser mask or the substrate to position the second block of the laser mask over the portion of the silicon film and irradiating a second laser beam through the second block.