Semiconductor device and method for fabricating the same

A semiconductor device comprising:

• a substrate;
• a first element separation film and a second element separation film which are in the substrate and are adjacent to each other;
• a trench which includes a first portion in the first element separation film and a second portion in the substrate between the first element separation film and the second element separation film, a bottom face of the first portion above a bottom face of the second portion, connecting side walls for connecting the bottom face of the first portion with the bottom face of the second portion defined by the first element separation film;
• and
• a storage contact which fills the trench, wherein
• the substrate and the storage contact include single crystal silicon.

A method for fabricating a semiconductor device, the method comprising:

• forming a bit line structure on a substrate, the substrate including an element separation film;
• forming a trench in the element separation film and in the substrate on at least one side of the bit line structure, the trench including a first portion in the element separation film and a second portion in the substrate, a bottom face of the first portion above a bottom face of the second portion;
• forming a storage contact in the trench;
• irradiating the storage contact with a laser to recrystallize the storage contact;
• and
• forming a landing pad on the storage contact, wherein
• the storage contact is a single crystal storage contact.