Trench isolation structure and fabrication method thereof

• Main Author: RHA; KWAN GOO
• Format: Patent
• Language: English
• Published: 03.10.2000
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Trench isolation structure includes a first conformal insulating film (preferably consisting of silicon nitride) which lines a trench etched in a silicon substrate, an insulating layer (preferably consisting of silicon dioxide) which caps the lines trench and thereby forms a cavity, and a gas (preferably consisting of carbon dioxide) within the cavity. Fabrication of the trench isolation structure is begun by depositing a first conformal insulating film onto the surface of a trench etched in a silicon substrate, thereby forming a lined trench. An amorphous carbon layer is deposited within the lined trench and the lined trench is capped by an insulating layer which encloses the amorphous carbon within a cavity. The solid amorphous carbon within the cavity is converted to carbon dioxide gas by annealing the substrate in an oxidizing ambient. Planarizing the insulating layer to the level of the substrate completes fabrication of the trench isolation structure.