Semiconductor device and method of fabricating the same

A method of fabricating a semiconductor device, said method comprising the steps of:

• forming a semiconductor film over a substrate;
• forming a first insulating layer between the substrate and the semiconductor film;
• providing a tensile stress to the first insulating layer and the semiconductor film by a heat treatment;
• forming a semiconductor island as an active layer by separating the semiconductor film;
• and
• forming a second insulating layer having a compressive stress at an opposite side to the substrate of the active layer.

A method of fabricating a semiconductor device, said method comprising the steps of:

• forming a semiconductor island having a tensile stress as an active layer over a substrate;
• forming a first insulating layer having a tensile stress between the substrate and the active layer;
• forming a second insulating layer having a compressive stress at an opposite side to the substrate of the active layer;
• and
• forming an electrode for applying a voltage to the active layer through the second insulating layer.

A method of fabricating a semiconductor device, said method comprising the steps of:

• forming a semiconductor island having a tensile stress as an active layer over a substrate;
• forming an electrode for applying a voltage to the active layer through a first insulating layer;
• forming the first insulating layer having a tensile stress between the substrate and the active layer;
• and
• forming a second insulating layer having a compressive stress at an opposite to the substrate of the active layer.

A method of fabricating a semiconductor device including a thin film transistor, said method comprising the steps of:

• forming a first silicon nitride oxide film including nitrogen at a first concentration on an insulating surface;
• forming a second silicon nitride oxide film including nitrogen at a second concentration on the first silicon nitride oxide film;
• forming a crystalline semiconductor island on the second silicon nitride oxide film;
• forming a gate insulating film comprising a third silicon nitride oxide film including nitrogen at a third concentration on the crystalline semiconductor island;
• forming a gate electrode over the crystalline semiconductor island with the gate insulating film therebetween;
• forming an interlayer insulating film on the gate electrode and the gate insulating film,
• wherein the first concentration is higher than each of the second and third concentrations,
• wherein the first silicon nitride oxide film has a tensile stress while each of the second silicon nitride oxide film and the interlayer insulating film has a compressive stress.