Patent ID: 6288413
Filing Date: 2001-09-11
Classification: H01L

Abstract:
A thin film transistor comprising:an insulating substrate;a semiconductor layer of a polycrystalline silicon formed on said insulating substrate;a gate insulator film formed so as to contact said semiconductor layer;a gate electrode formed so as to contact said gate insulator film;an active layer formed in a region of said semiconductor layer corresponding to said gate electrode;a first semiconductor region which is formed in said semiconductor layer outside of said active layer which has an impurity concentration of higher than or equal to 1.times.10.sup.18 cm.sup.-3 and lower than 1.times.10.sup.20 cm.sup.-3 ; anda second semiconductor region which is formed in said semiconductor layer outside of said first semiconductor region and which has an impurity concentration of higher than that of said first semiconductor region, said second semiconductor region having the same conductive type as that of said first semiconductor region,wherein said first semiconductor region is formed between said second semiconductor region and said insulating substrate.