| CPC H01L 29/7848 (2013.01) [H01L 21/02532 (2013.01); H01L 21/76224 (2013.01); H01L 21/764 (2013.01); H01L 27/0886 (2013.01); H01L 29/41791 (2013.01)] | 20 Claims | 

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               1. A device comprising: 
            a fin structure disposed on a substrate; 
                a source/drain feature disposed on the fin structure; 
                a first etch stop layer disposed over the fin structure; 
                a second etch stop layer disposed over the fin structure and spaced apart from the first etch stop layer; 
                a source/drain contact disposed on the source/drain feature and interfacing with at least one of the first and second etch stop layers; and 
                an air gap disposed along the source/drain contact such that the source/drain feature and at least one of the first and second etch stop layers are exposed to the air gap. 
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