Transistor devices having vertically stacked carbon nanotube channels and techniques for the fabrication thereof are provided. In one aspect, a transistor device is provided. The transistor device includes a substrate; a bottom gate embedded in the substrate with a top surface of the bottom gate being substantially coplanar with a surface of the substrate; a stack of device layers on the substrate over the bottom gate, wherein each of the device layers in the stack includes a first dielectric, a carbon nanotube channel on the first dielectric, a second dielectric on the carbon nanotube channel and a top gate on the second dielectric; and source and drain contacts that interconnect the carbon nanotube channels in parallel. A method of fabricating a transistor device is also provided.