Metal oxide semiconductor device with self-aligned groove channel and method for manufacturing the same

A metal oxide semiconductor device with a self-aligned groove channel structure comprising:

• a substrate in which a first channel region of a first conductivity type and source and drain regions of a second conductivity type are formed, a first gate insulating layer formed on the first channel region, and a first gate electrode formed in contact with the gate insulating layer;
• a second gate electrode having a self-aligned groove structure formed in the substrate at first and second sides of the first gate electrode and the first channel region;
• a second gate insulating layer formed in surface contact with the groove structure and between the substrate and the second gate electrode;
• a non-planar second channel region of the first conductivity type formed under the second gate insulating layer and doped with a different concentration of an impurity from the first channel region and wherein
• the self-aligned groove structure comprises first and second grooves respectively disposed at the first and second sides of the first gate electrode and the first channel region, each groove having first and second sidewalls extending vertically in the substrate, the first sidewall of the first groove extending from a top surface of the first channel region downward to a bottom of the first groove in the substrate and the second sidewall of the first groove extending upward from the bottom of the first groove to a top surface of one of the source and drain regions and the first sidewall of the second groove extending from the top surface of the first channel region downward to a bottom of the second groove and the second sidewall of the second groove extending upward from the bottom of the second groove to a top surface of another of the source and drain regions.