Abstract: A split-gate semiconductor device is fabricated by forming floating gates on the sidewalls of the control gates of transistors, then using a bottom anti-reflective coating as a mask while removing unnecessary floating gates, preferably by an isotropic dry etching process that removes floating-gate material from the sidewalls faster than it removes dielectric material from the upper parts of the control gates. Alternatively, control gate structures are formed, floating-gate material is deposited, removed, then deposited again to form floating gates on the sidewalls of the control gate structures, and the central parts of the control gate structures are etched to leave control gates with floating gates on one sidewall each.

Abstract: A split-gate semiconductor device is fabricated by forming floating gates on the sidewalls of the control gates of transistors, then using a bottom anti-reflective coating as a mask while removing unnecessary floating gates, preferably by an isotropic dry etching process that removes floating-gate material from the sidewalls faster than it removes dielectric material from the upper parts of the control gates. Alternatively, control gate structures are formed, floating-gate material is deposited, removed, then deposited again to form floating gates on the sidewalls of the control gate structures, and the central parts of the control gate structures are etched to leave control gates with floating gates on one sidewall each.