Semiconductor device structure with air gap structure and method for forming the same

A semiconductor device structure, comprising:

• a first conductive contact disposed over a first source/drain region of a semiconductor substrate;
• a first energy removable structure adjoins a lower portion of a sidewall of the first conductive contact, wherein a first air gap structure is enclosed by the first energy removable structure;
• a second energy removable structure adjoins an upper portion of the sidewall of the first conductive contact, wherein a second air gap structure is enclosed by the second energy removable structure;
• and
• a first dielectric layer disposed between the first energy removable structure and the second energy removable structure, wherein the first dielectric layer adjoins a middle portion of the sidewall of the first conductive contact.

A method for forming a semiconductor device structure, comprising:

• forming a first energy removable layer over a semiconductor substrate;
• forming a first dielectric layer over the first energy removable layer;
• forming a second energy removable layer over the first dielectric layer;
• forming a conductive contact penetrating through the first energy removable layer, the first dielectric layer and the second energy removable layer;
• and
• performing a heat treatment process to transform the first energy removable layer into a first energy removable structure and to transform the second energy removable layer into a second energy removable structure, wherein a first air gap structure is enclosed by the first energy removable structure and a second air gap structure is enclosed by the second energy removable structure.