A technique relates to forming a sidewall tunnel junction. A first conducting layer is formed using a first shadow mask evaporation. A second conducting layer is formed on a portion of the first conducting layer, where the second conducting layer is formed using a second shadow mask evaporation. An oxide layer is formed on the first conducting layer and the second conducting layer. A third conducting layer is formed on part of the oxide layer, such that the sidewall tunnel junction is positioned between the first conducting layer and the third conducting layer.