Process for the manufacture of integrated devices with gate oxide protection from manufacturing process damage, and protection structure therefor

A process for the manufacture of integrated devices with gate oxide protection from manufacturing process damage, comprising:

• forming a zener diode, said forming a zener diode comprising,
• in a substrate having a first conductivity type, implanting doping species having a second conductivity type to form a well in said substrate having a first conductivity level;
• implanting doping species of said second conductivity type in a first area of said well to form a first conductive region having a second conductivity level higher than said first conductivity level;
• implanting doping species of said first conductivity level in said well, at least partially adjacent to said first area, so as to form a second conductive region forming, with said first conductive region, said zener diode, wherein implanting doping species of said second conductivity type further comprises implanting said doping species of said second conductivity type in a second area of said well, remote from said first area, so as to form a third conductive region of said second conductivity type and of said second conductivity level, not crossing said second conductive region;
• forming an electrically insulating region covering said substrate, and forming a first metallic region extending above said electrically insulating region, said first metallic region having a portion crossing said electrically insulating region and being in direct electrical contact with said third conductive region;
• and
• implanting said doping species of said first conductivity type in an area of said substrate outside said well, to form a fourth conductive region of said first conductivity type and of a conductivity level higher than said substrate, and in that it comprises a step of forming a second metal region extending above, and insulated from said substrate, said second metal region electrically connecting said second conductive region and fourth conductive region.