Method to insulate contact plug with silicon carbon oxide and to insulate above bit line with silicon oxide by oxidating silicon carbon oxide

Abstract

A semiconductor structure and a method for manufacturing the same are provided. The semiconductor structure includes: a substrate, bit line structures, and an isolation structure. The substrate includes multiple active areas. The bit line structures are located above the active areas, and include multiple bit lines extending in a first direction parallel to the surface of the substrate and multiple contact plugs electrically connected to the bit lines and the active areas. The isolation structure includes a first insulating layer including a first part and a second part located below the first part, a second insulating layer covering the surface of the second part and a third insulating layer covering at least the surface of the first part. The first part covers at least side walls of the bit lines, and the second part covers at least side walls of the contact plugs.