Patent ID: 9240345
Filing Date: 2016-01-19
CPC Classification: H01L

Claim Text:
1. A method of forming an isolation trench that isolates an integrated device from a neighboring integrated device, the method comprising: forming a trench of the isolation trench in an upper surface of a substrate and between a first integrated device location and a second integrated device location, wherein an inner surface of the trench includes a first lateral surface associated with the first integrated device location, a second lateral surface associated with the second integrated device location, and a bottom surface that connects the first lateral surface and the second lateral surface; forming an inner wall oxide layer on the inner surface of the trench such that the inner wall oxide layer includes an upper surface and lower surface that are each conformal with the first lateral surface, the second lateral surface, and the bottom surface of the trench; forming a liner layer on the inner wall oxide layer such that the liner layer includes an upper surface and a lower surface that are each conformal with the upper surface of the inner wall oxide layer and the first lateral surface, the second lateral surface, and the bottom surface of the trench; and removing at least a portion of the inner wall oxide layer, wherein the removed portion of the inner wall oxide layer creates an air gap between the inner surface of the trench and the lower surface of the liner layer.