METHOD OF SEALING AN AIR GAP IN A LAYER OF A SEMICONDUCTOR STRUCTURE AND SEMICONDUCTOR STRUCTURE

摘要

A method of sealing an air gap (6) in a layer (2) of a semiconductor structure comprises providing a first layer (2) of the semiconductor structure having at least one air gap (6) for providing isolation between at least two conductive lines (4) formed in the first layer. The at least one air gap extends into the first layer from a first surface (8) of the first layer. The method further comprises forming a barrier layer (10, 16) of a barrier dielectric material over the first surface (8) of the first layer and the at least one air gap. The barrier dielectric material is selected to have a dielectric constant less than 3.5 and to provide a barrier to prevent chemicals entering the at least one air gap. In another embodiment, the at least one air gap (500) extends from a first surface (420) of the first layer to at least a portion of side surfaces of the at least two conductive lines to expose at least a portion of the side surfaces, and a barrier layer (600) of a barrier dielectric material is formed over the exposed portions of the side surfaces of each of the at least two conductive lines.