POLYSILICON THIN-FILM TRANSISTOR AND ACTIVE MATRIX TYPE LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To effectively block mixture of migratory ions from a glass substrate and to effectively suppress microcracks. ;SOLUTION: While a thin-film transistor structure, wherein mixture of migratory ions from a glass substrate is suppressed, is actualized by arranging an undercoat layer in double-layered structure of an SiN undercoat layer 10 and an SiO film undercoat layer 11 on a glass substrate 1, a source-drain region 4, an LDD region 9, and a polysilicon region of a channel polysilicon layer 3 as elements of a thin-film transistor thereupon, and then a gate line layer 6 at the part corresponding to the channel polysilicon layer 3 across a gate insulating film 5, microcracks are suppressed by making the undercoat layer at least correspond to the polyslicon region including the source-drawin region 4, LDD region 9, and channel polysilicon layer 3 thicker than other regions.;COPYRIGHT: (C)1999,JPO