Patent ID: 8071459
Filing Date: 2011-12-06
Classification: H01L

Abstract:
1. A method of sealing an air gap in a layer of a semiconductor structure, the method comprising: providing a first layer of the semiconductor structure having at least one air gap for providing isolation between at least two conductive lines formed in the first layer, the at least one air gap extending into the first layer from a first surface of the first layer; forming a first dielectric layer on the first surface of the first layer such that the first dielectric layer closes the at least one air gap; forming a barrier layer of a first barrier dielectric material over the first dielectric layer by depositing conformally the barrier material over the first dielectric layer, the barrier layer having a thickness in the range of 1-10 nm and the first barrier dielectric material being 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; and forming, over the barrier layer, a second dielectric layer having at least one air gap for providing isolation between at least two conductive lines formed in the second dielectric layer.