Patent ID: 7456428
Filing Date: 2008-11-25
Classification: C30B,H01L

Abstract:
1. An image display device, comprising a thin film transistor where a semiconductor thin film of a substantially belt-shaped crystal is used as a channel; wherein said substantially belt-shaped crystal is crystallized by scanning laser light or a substrate to irradiate said laser light onto an arbitrary region of said semiconductor thin film and performing a laser irradiation thereon, said substantially belt-shaped crystal being crystallized such that crystalline grains grow in said scanning direction, said semiconductor thin film being formed on said substrate, wherein, on XY coordinates where value x of beam size W (μm) of said laser light measured in substantially the same direction as said scanning direction is defined as X axis, and where value y of scanning velocity Vs (m/s) is defined as Y axis, said crystallization processing is performed within a region where all of the following (condition 1), (condition 2), and (condition 3) hold, (condition 1) said beam size W is larger than wavelength of said laser beam, (condition 2) said scanning velocity Vs is smaller than upper-limit of crystal growth speed, and (condition 3) x×(1/y)<25 μs.