Method to reduce leakage in a protection diode structure

A method for forming a protection diode device, comprising:

• forming a well region of a first conductivity type in a top portion of a semiconductor substrate;
• forming at least one trench isolation structure in said well region, said trench isolation structure extending above a surface of said well region;
• forming a first heavily doped region of a second conductivity type in said well region;
• forming a silicide resistant block-out structure covering said trench isolation structure and laterally extending to a peripheral region of said first heavily doped region adjacent said trench isolation structure;
• and
• selectively forming a metal silicide layer on an uncovered portion of said first heavily doped region,
• wherein said silicide resistant block-out structure comprises a polysilicon layer laterally, surrounded by insulating spacers.

A method for forming a protection diode device, comprising:

• forming a well region of a first conductivity type in a top portion of a semiconductor substrate;
• forming at least one trench isolation structure in said well region, said trench isolation structure extending above a surface of said well region;
• forming a first heavily doped region of a second conductivity type in said well region;
• forming a silicide resistant block-out structure covering said trench isolation structure and laterally extending to a peripheral region of said first heavily doped region adjacent said trench isolation structure;
• and
• selectively forming a metal silicide layer on an uncovered portion of said first heavily doped region,
• further comprising forming a second heavily doped region of said first conductivity type in further portions of said well region before said forming a silicide resistant block-out structure,
• wherein said forming a second heavily doped region includes forming said second heavily doped region at said peripheral region of said first heavily doped region adjacent said trench isolation structure.