Device for protecting an integrated circuit chip against attacks

A method of forming an integrated circuit chip, comprising:

• forming first and second wells of first and second conductivity types, respectively, formed in an upper portion of a semiconductor substrate of the first conductivity type;
• forming a first plurality of MOS transistors having a channel of the second conductivity type formed in the first well;
• forming a second plurality of MOS transistors having a channel of the first conductivity type formed in the second well, the transistors of the second plurality being inverter-connected with the transistors of the first plurality, respectively;
• and
• forming a protection device configured to protect the integrated circuit chip against attacks, forming the protection device including:
• forming a protection layer of the second type extending under and contacting the first and second wells;
• forming a lateral insulation region between the wells, said lateral insulation region extending from an upper surface of the substrate to said layer, wherein said lateral insulation region includes a trench with insulated walls and filled with a conductive material;
• and
• forming a detector associated with said lateral insulation region, said detector being configured to detect variations of a voltage of the conductive material of said lateral insulation region.

A method, comprising:

• protecting an integrated circuit chip against attacks using a protection device, the integrated circuit chip including:
• first and second wells of first and second conductivity types, respectively, formed in an upper portion of a semiconductor substrate having a first conductivity type;
• a first plurality of MOS transistors having a channel of the second conductivity type formed in the first well;
• a second plurality of MOS transistors having a channel of the first conductivity type formed in the second well, the transistors of the second plurality being inverter-connected with the transistors of the first plurality, respectively, wherein the protection device includes:
• a protection layer of the second conductivity type extending under and contacting the first and second wells;
• and
• a lateral insulation region between the wells, said lateral insulation region extending from an upper surface of the substrate to said layer and including a trench with insulated walls and filled with a conductive material;
• and
• detecting variations of a voltage of the conductive material of the lateral insulation region in the chip using a detector associated with said lateral insulation region.

An integrated circuit chip comprising:

• first and second wells of first and second conductivity types, respectively, formed in an upper portion of a semiconductor substrate of the first conductivity type;
• and
• a protection device configured to protect the integrated circuit chip against attacks, the protection device including:
• a protection layer of the second conductivity type extending under and contacting the first and second wells;
• a lateral insulation region between the wells, said lateral insulation region extending from an upper surface of the substrate to said protection layer, wherein said lateral insulation region includes a trench with insulated walls and filled with a conductive material;
• and
• a detector associated with said lateral insulation region, said detector being configured to detect variations of a voltage of the conductive material of said lateral insulation region.