Semiconductor devices and methods for manufacturing the same, and nand memory devices

A semiconductor device, comprising:

• a substrate comprising a first active region and an isolation region surrounding the first active region, the first active region comprising a first channel region sandwiched between a first source region and a first drain region in a lateral direction;
• a first groove located between the isolation region and the first channel region, the first groove being partially located in the isolation region without penetrating the isolation region;
• a first gate insulating layer covering the first groove and the first channel region;
• and
• a first gate located on the first gate insulating layer, and covering the first channel region and filling the first groove.

A NAND memory device, comprising:

• a memory array comprising a plurality of memory cell strings;
• and
• a periphery device electrically connected with the memory array, comprising:
• a substrate comprising a first active region and an isolation region located on a periphery of the first active region, the first active region comprising a first channel region sandwiched between a first source region and a first drain region in a lateral direction,
• a first groove located between the isolation region and the first channel region, the first groove being partially located in the isolation region without penetrating the isolation region,
• a first gate insulating layer covering the first groove and the first channel region, and
• a first gate located on the first gate insulating layer, the first gate covering the first channel region and filling the first groove.