Abstract: There is provided a method for forming a vertical gate on a vertical array semiconductor device having support devices. The method includes the step of forming a pedestal of the vertical gate from SiGe. The pedestal is etched in a gate conductor (GC) post etch treatment (PET) that is selective with respect to the support devices. A trench top nitride spacer process is performed to obtain a GC SiN spacer combined with a DT (deep trench) top SiN spacer, wherein the GC SiN spacer and the DT top SiN spacer isolate a bitline contact from the vertical gate with respect to critical dimension and overlay.