Buried zener diode and method of forming the same.

摘要

A buried zener diode and fabrication method are disclosed in which contacts are made to the underside of the anode (56) by means of lateral contact regions (58) and an underlying contact layer (50), as opposed to the prior technique of making contact to lateral portions of the anode (12) through a lightly doped well (8). The fabrication method reduces the number of fabrication steps required by forming the contact layer (50), anode (56) and lateral contact regions (58) in the same steps as those used to form the surrounding isolation ring in an "up-down" diffusion process.