Semiconductor device

A semiconductor device comprising:

• a crystalline semiconductor film;
• a channel formation region provided in the crystalline semiconductor film, the crystalline semiconductor film comprising silicon and germanium at least in the channel formation region;
• a source region and a drain region sandwiching the channel formation region therebetween;
• a gate electrode provided adjacent to the channel formation region with a gate insulating film therebetween;
• and
• an impurity region provided between the channel formation region and at least one of the source region and the drain region and comprising a part overlapping the gate electrode,
• wherein 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;
• and
• secondary ion mass spectroscopy is conducted on the channel formation region to reveal that the region contains less than 5×1018 nitrogen atoms per cm3, less than 5×1018 carbon atoms per cm3, and less than 1×1019 oxygen atoms per cm3,
• the crystalline semiconductor film contains germanium in a concentration of equal to or more than 0.1 atomic percent and equal to or less than 10 atomic percent at least in the channel region.

A semiconductor device whose pixel portion and driver circuit are formed over a same insulator,

• the driver circuit is composed of an n-channel thin film transistor and a p-channel thin film transistor;
• at least the n-channel thin film transistor comprising;
• a crystalline semiconductor film;
• a channel formation region provided in the crystalline semiconductor film, the crystalline semiconductor film comprising silicon and germanium at least in the channel formation region;
• a source region and a drain region sandwiching the channel formation region therebetween;
• a gate electrode provided adjacent to the channel formation region with a gate insulating film therebetween;
• and
• an impurity region provided between the channel formation region and at least one of the source region and the drain region and comprising a part overlapping the gate electrode,
• wherein 20% or more of the crystalline semiconductor film 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 crystalline semiconductor film 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 crystalline semiconductor film 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;
• and
• secondary ion mass spectroscopy is conducted on the crystalline semiconductor film to reveal that the film contains less than 5×1018 nitrogen atoms per cm3, less than 5×1018 carbon atoms per cm3, and less than 1×1019 oxygen atoms per cm3.

A semiconductor device having a pixel thin film transistor over an insulator, said pixel thin film transistor comprising:

• a crystalline semiconductor film;
• a channel formation region provided in the crystalline semiconductor film, the crystalline semiconductor film comprising silicon and germanium at least in the channel formation region;
• a source region and a drain region sandwiching the channel formation region therebetween;
• a gate electrode provided adjacent to the channel formation region with a gate insulating film therebetween;
• and
• an impurity region provided between the channel formation region and at least one of the source region and the drain region and comprising a part overlapping the gate electrode,
• wherein 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;
• and
• secondary ion mass spectroscopy is conducted on the channel formation region to reveal that the region contains less than 5×1018 nitrogen atoms per cm3, less than 5×1018 carbon atoms per cm3, and less than 1×1019 oxygen atoms per cm3.