Patent ID: 7566656
Filing Date: 2009-07-28
Classification: H01L

Abstract:
1. A method for forming a void in a structure comprising: providing a structure on a substrate, wherein the structure includes an intermediate layer between upper and lower layers, wherein the intermediate layer can be etched selectively to the upper and lower layers; forming a trench in the structure; depositing a device layer over the substrate on the upper layer and lining the trench and forming first sidewall spacers lining sidewalls of the trench from the device layer; forming second sidewall spacers in the trench on the first sidewall spacers, the first and second sidewall spacers can be etched selectively to each other; forming a barrier layer to line the second sidewall spacers in the trench; filling the trench with a fill material; and removing the first sidewall spacers and at least a portion of the intermediate layer selective to the second sidewall spacers and upper and lower layers to form voids in the structure between the upper and lower layers adjacent to the trench with the fill material, wherein the upper layer over the voids is present prior to and during the removing of the first sidewall spacers and at least a portion of the intermediate layer.