Patent ID: 7700947
Filing Date: 2010-04-20
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor film on an insulating surface, the semiconductor film comprising an n-type impurity region containing a periodic table group 15 element, wherein a concentration of the periodic table group 15 element varies in a gradient from the insulating surface, a channel forming region, and a gate electrode adjacent to the channel forming region, wherein the n-type impurity region contains a metallic element for promoting crystallization of silicon, wherein a thickness of a first region of the n-type impurity region where a first concentration of the periodic table group 15 element is 1×10 wherein the maximum value of a second concentration of the periodic table group 15 element in a second region of the n-type impurity region is 1×10 wherein the first region is on the insulating surface, and wherein the second region is over the first region.