Semiconductor device and method for fabricating the same

A semiconductor device, comprising:

• a semiconductor substrate including an active region and an isolation layer;
• a plurality of bit lines over the semiconductor substrate;
• a line-type opening that is formed between the bit lines and includes a recess which exposes the active region and the isolation layer;
• a silicon-containing pad selectively grown on the exposed active region;
• a plug isolation structure that is formed inside the line-type opening to expose the silicon-containing pad and defines a contact hole having a smaller landing area than a surface area of an upper portion of the silicon-containing pad;
• and
• a silicon-containing plug formed on the silicon-containing pad inside the contact hole,
• wherein the silicon-containing pad comprising:
• a central portion formed on the active region;
• and
• a side extended portion that laterally grows up from the central portion to extend over the isolation layer.