Semiconductor devices and methods of manufacturing the same

A method of manufacturing a semiconductor device, comprising:

• forming an optical element on a single crystalline substrate, the optical element comprising an optical waveguide extending in a crystal orientation <010>;
• and
• forming an electrical element comprising a gate electrode extending in a crystal orientation <110>, and source and drain regions adjacent to the gate electrode, the source and drain regions arranged in a direction substantially perpendicular to a direction in which the gate electrode extends,
• wherein forming the optical element comprises:
• forming a first cladding layer on the single crystalline substrate;
• forming an amorphous layer on the first cladding layer and the single crystalline substrate;
• crystallizing the amorphous layer to form an epitaxial layer having a crystal orientation substantially the same as that of the single crystalline substrate;
• partially removing the epitaxial layer to form a core layer extending in a crystal orientation <010>;
• and
• forming a second cladding layer on the first cladding layer to cover the core layer.

A method of manufacturing a semiconductor device, comprising:

• forming an optical element on a single crystalline substrate, the optical element comprising an optical waveguide extending in a crystal orientation <010>;
• and
• forming an electrical element comprising a gate electrode extending in a crystal orientation <110>, and source and drain regions adjacent to the gate electrode, the source and drain regions arranged in a direction substantially perpendicular to a direction in which the gate electrode extends,
• wherein forming the electrical element comprises:
• forming a buried insulation layer on the single crystalline substrate;
• forming an amorphous layer on the buried insulation layer;
• crystallizing the amorphous layer to form an epitaxial layer having a crystal orientation substantially the same as that of the single crystalline substrate;
• forming the gate electrode on the epitaxial layer;
• and
• forming the source region and the drain region adjacent to the gate electrode, the source region and the drain region being at upper portions of the epitaxial layer.