In one embodiment, a mandrel and an outer dummy spacer may be employed to form a first conductivity type region. The mandrel is removed to form a recessed region wherein a second conductivity type region is formed. In another embodiment, a mandrel is removed from within shallow trench isolation to form a recessed region, in which an inner dummy spacer is formed. A first conductivity type region and a second conductivity region are formed within the remainder of the recessed region. An anneal is performed so that the first conductivity type region and the second conductivity type region abut each other by diffusion. A gate electrode is formed in self-alignment to the p-n junction between the first and second conductivity regions. The p-n junction controlled by the gate electrode, which may be sublithographic, constitutes an inventive tunneling effect transistor.