The orientation of a crystalline semiconductor film obtained by
crystallizing an amorphous semiconductor film is improved and a TFT formed
from this crystalline semiconductor film is provided. In a semiconductor
device whose TFT is formed from a semiconductor layer mainly containing
silicon, the semiconductor layer has a channel formation region and an
impurity region doped with an impurity of one type of conductivity. 20% or
more of the channel formation region is the {101} lattice plane that forms
an angle of equal to or less than 10 degree with respect to the surface of
the crystalline semiconductor film, the plane being detected by an
electron backscatter diffraction pattern method, 3% or less of the channel
formation region is the {001} lattice plane that forms an angle of equal
to or less than 10 degree with respect to the surface of the crystalline
semiconductor film, 5% or less of the channel formation region is the
{111} lattice plane that forms an angle of equal to or less than 10 degree
with respect to the surface of the crystalline semiconductor film.
