Semiconductor memory element, semiconductor memory device and method of fabricating the same

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the semiconductor active layer is a polycrystal semiconductor film constituted by aggregating a plurality of crystal grains elongated in the same direction;
• and
• wherein a grain boundary of the crystal grain constituting the polycrystal semiconductor film is flat or formed with a recessed portion.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the channel region is a polycrystal semiconductor film crystallized by being irradiated with a continuously oscillating laser beam at least in the same channel region;
• and
• wherein a surface roughness of the channel region is 0.1 nm through 60 nm in a P-V value.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode;

• wherein the semiconductor memory element is formed over a substrate having an insulating surface,
• wherein the semiconductor active layer is a polycrystal semiconductor film constituted by aggregating a plurality of crystal grains elongated in the same direction;
• and
• wherein a surface roughness of the channel region is 0.1 nm through 60 nm in a P-V value.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the channel region is a polycrystal semiconductor film crystallized by being irradiated with a continuously oscillating laser beam at least in the same channel region;
• and
• wherein a surface roughness of the channel region is 0.1 nm through 5 nm in an rms value.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the semiconductor active layer is a polycrystal semiconductor film constituted by aggregating a plurality of crystal grains elongated in the same direction;
• and
• wherein a surface roughness of the channel region is 0.1 nm through 5 nm in an rms value.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the semiconductor active layer is a crystallized polycrystal semiconductor film;
• wherein the semiconductor active layer is constituted by aggregating a plurality of crystal grains elongated in the same direction;
• and
• wherein a grain boundary of a crystal grain in the polycrystal semiconductor film is flat or formed with a recessed portion.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the channel region is a crystallized polycrystal semiconductor film;
• and
• wherein a surface roughness of the channel region is 0.1 nm through 60 nm in a P-V value.

A semiconductor memory element comprising a semiconductor active layer comprising a channel region and one conductive type impurity region, a first gate insulating film, a charge accumulating layer, a second gate insulating film, and a control gate electrode,

• wherein the semiconductor memory element is formed over a substrate having an insulating surface;
• wherein the channel region is a crystallized polycrystal semiconductor film;
• and
• wherein a surface roughness of the channel region is 0.1 nm through 5 nm in an rms value.