SHALLOW TRENCH ISOLATION LAYER WITH AIR GAP FOR INCREASING DIELECTRIC CONSTANT AND SPACER FOR PREVENTING LEAKAGE CURRENT AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: An STI(Shallow Trench Isolation) layer and a manufacturing method thereof are provided to increase dielectric constant of the isolation layer by using an air gap and to prevent leakage current due to voids of a substrate surface and over-etching into the air gap by using a spacer. CONSTITUTION: An STI layer includes a spacer, an etched groove, an air gap and a gap-fill insulating layer. The spacer(112a) made of insulating material is formed at inner sidewalls of a trench. The etched groove is formed under the trench. The air gap(118) is formed in the groove. The gap-fill insulating layer(116a) is filled in the groove and trench except the air gap.