Vertical PIN diodes and method of manufacturing them

The invention concerns a method of manufacturing a vertical PIN diode (30) comprising: providing an epitaxial wafer comprising a vertically stacked N-type layer (32), intrinsic layer (33) and P-type layer (34); forming an anode contact of the vertical PIN diode (30) by forming an anode metallization (35) on a first portion of the P-type layer defining an anode region (34a); forming an electrically insulating layer (36) around the anode region (34a) such that a first portion of the intrinsic layer (33) extends vertically between the N-type layer (32) and the anode region (34a) and second portions of the intrinsic layer (33) extend vertically between the N-type layer (32) and the electrically insulating layer (36); forming a trench (38) in the electrically insulating layer (36) and in the second portions of the intrinsic layer (33) so as to expose a portion of the N-type layer (32) defining a cathode region and to define a sacrificial side-guard ring (36a) consisting of a portion of the electrically insulating layer (36) that extends laterally between the trench (38) and the anode region (34a) and laterally surrounds said anode region (34a); and forming a cathode contact of the vertical PIN diode (30) by forming a cathode metallization (39) on the exposed portion of the N-type layer (32) defining the cathode region.