Patent ID: 9378975
Filing Date: 2016-06-28
CPC Classification: H01L

Claim Text:
1. A method of forming a spacer, the method comprising: positioning a substrate on a substrate holder in a plasma processing chamber, the substrate having a silicon nitride film covering structures on the substrate and a low-k film covering the silicon nitride film, the silicon nitride film and the low-k film substantially conforming to geometry of structures on the substrate; executing an anisotropic etch process that etches a portion of the low-k film using plasma products from a halogen-containing process gas mixture such that the low-k film is removed from first structures while remaining on second structures that are taller than the first structures, executing the anisotropic etch process deposits a CFy-based polymer on exposed silicon nitride surfaces; and executing an isotropic etch process that etches silicon nitride using plasma products from an oxygen-based process gas.