Disclosed is a Zener diode having a scalable reverse-bias breakdown voltage (Vb) as a function of the position of a cathode contact region relative to the interface between adjacent cathode and anode well regions. Specifically, cathode and anode contact regions are positioned adjacent to corresponding cathode and anode well regions and are further separated by an isolation region. However, while the anode contact region is contained entirely within the anode well region, one end of the cathode contact region extends laterally into the anode well region. The length of this end can be predetermined in order to selectively adjust the Vb of the diode (e.g., increasing the length reduces Vb of the diode and vice versa). Also disclosed are an integrated circuit, incorporating multiple instances of the diode with different reverse-bias breakdown voltages, a method of forming the diode and a design structure for the diode.