Semiconductor device and method of manufacturing the same

A semiconductor device comprising:

• an isolation region;
• a semiconductor region defined by the isolation region;
• first and second grooves in the semiconductor region, the first and second grooves extending in parallel to each other, each of the first and second grooves having first and second ends, the first and second ends reaching the isolation region;
• and
• insulating films in the first and second grooves.

A semiconductor device comprising:

• a semiconductor substrate;
• an insulating film in a surface region of the semiconductor substrate, the insulating film defining a semiconductor region of the semiconductor substrate;
• first and second grooves in the semiconductor region, the first and second grooves extending in a first direction, the first and second grooves being disposed adjacent to each other, the ends of each of the first and second grooves reaching the insulating film;
• insulators in the first and second grooves;
• and
• a buried bit line in the semiconductor region, the buried bit line extending in the first direction, the buried bit line being in contact with the insulators.