Semiconductor devices having stressed active regions therein and methods of forming same

A method of fabricating a semiconductor device, comprising:

• providing a substrate in which a first semiconductor film, a buried insulating film and a second semiconductor film are sequentially stacked;
• forming a first trench extending in a first direction in the second semiconductor film;
• performing an epitaxial growth process using the second semiconductor film as a seed to form a semiconductor pattern extending in the first direction;
• forming a second trench defining a sidewall of the semiconductor pattern extending in a second direction intersecting the first direction;
• and
• forming an element isolation film which fills the first trench and the second trench.

A method of fabricating a semiconductor device, comprising:

• providing a substrate including a semiconductor material therein having a first lattice constant;
• forming a semiconductor pattern having a second lattice constant greater than the first lattice constant on the semiconductor material, the semiconductor pattern having a first sidewall and a second sidewall intersecting the first sidewall;
• forming an element isolation film which surrounds the first sidewall and the second sidewall, on the substrate;
• and
• forming a gate electrode intersecting the second sidewall on the semiconductor pattern and the element isolation film;
• wherein a first angle formed between a lower surface of the semiconductor pattern and the first sidewall is greater than a second angle formed between the lower surface of the semiconductor pattern and the second sidewall.