Semiconductor device and manufacturing method thereof
View Patent ↗An object is to provide a semiconductor device with improved reliability in which a defect stemming from an end portion of a semiconductor layer provided in an island shape is prevented, and a manufacturing method thereof. Over a substrate having an insulating surface, an island-shaped semiconductor layer is formed, a first alteration treatment is performed, a first insulating film is formed on a surface of the island-shaped semiconductor layer, the first insulating film is removed, a second alteration treatment is performed on the island-shaped semiconductor from which the first insulating film is removed, a second insulating film is formed on a surface of the island-shaped semiconductor layer, and a conductive layer is formed over the second insulating film. An upper end portion of the island-shaped semiconductor layer has curvature by the first alteration treatment and the second alteration treatment.
1. A semiconductor device comprising:
a substrate having an insulating surface,
an island-shaped semiconductor layer provided over the substrate;
an insulating film formed so as to cover the island-shaped semiconductor layer; and
a conductive layer provided over the island-shaped semiconductor layer with the insulating film interposed therebetween,
wherein an upper end portion of a cross-section of the island-shaped semiconductor layer has curvature,
wherein the island-shaped semiconductor layer has a film thickness of 10 nm to 30 nm inclusive, and
wherein when a film thickness of the island-shaped semiconductor layer is t (t>0) and a curvature radius of an end portion of a cross-section of the island-shaped semiconductor layer is r (r>0), a relationship of t and r satisfies a conditional equation (t/4)≦r≦t.
2. A semiconductor device comprising:
a substrate having an insulating surface;
an island-shaped semiconductor layer provided over the substrate;
an insulating film formed so as to cover the island-shaped semiconductor layer; and
a conductive layer provided over the island-shaped semiconductor layer with the insulating film interposed therebetween,
wherein an upper end portion and a lower end portion of a cross-section of the island-shaped semiconductor layer have curvature,
wherein the island-shaped semiconductor layer has a film thickness of 10 nm to 30 nm inclusive, and
wherein when a film thickness of the island-shaped semiconductor layer is t (t>0) and a curvature radius of an end portion of a cross-section of the island-shaped semiconductor layer is r (r>0), a relationship of t and r satisfies a conditional equation (t/4)≦r≦t.
3. The semiconductor device according to claim 1 , wherein the insulating film has a film thickness of 1 nm to 10 nm inclusive.
4. The semiconductor device according to claim 1 , wherein the insulating film includes a material of the island-shaped semiconductor layer.
5. The semiconductor device according to claim 2 , wherein the insulating film has a film thickness of 1 nm to 10 nm inclusive.
6. The semiconductor device according to claim 2 , wherein the insulating film includes a material of the island-shaped semiconductor layer.