In a first step towards fabricating a truly 3-dimensional (3-d) Joseph
son-junction array, we have fabricated a quasi-3-d one, i.e. an array
consisting of two 2-d arrays stacked on top of and capacitively- and i
nductively-coupled to one another. We discuss in detail the fabricatio
n techniques we have employed to create this novel type of an array. S
uch techniques include alignment using topological markers, electron-b
eam lithography, shadow evaporation, and planarization. We have fabric
ated different samples whose 2-d arrays consist of underdamped Al-Al2O
3-Al junctions in which either the Josephson-coupling energy E(J)=HBAR
i(c)/2e, where i(C) is the junction critical current, dominates the si
ngle-junction charging energy E(C)=e2/2C, where C is the junction capa
citance, or vice versa. With these arrays, we plan to study the intera
ction between vortices and/or charges.