Patent ID: 7224028
Filing Date: 2007-05-29
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor layer provided over an insulating surface; an insulating film provided over the semiconductor layer; and a gate electrode provided over the insulating film, wherein the gate electrode has a tapered side edge; wherein the semiconductor layer comprises a channel-forming region, a source region and a drain region; wherein the semiconductor layer further comprises an LDD region provided between the channel-forming region and at least one of the source region and the drain region, wherein the LDD region comprises a first region and a second region, wherein the first region of the LDD region overlaps with the gate electrode, wherein the second region of the LDD region is provided outside the gate electrode, wherein a first portion of the insulating film provided over the first region of the LDD region has a first thickness, wherein a second portion of the insulating film provided over the second region of the LDD region has a second thickness, wherein a third portion of the insulating film provided over the source region and the drain region has a third thickness, wherein the second thickness is thinner than the first thickness, and wherein the third thickness is thinner than the second thickness.