Resistor-diode ladder, esd protection circuit including same, semiconductor device including same, and method of manufacturing same

A method of forming a resistor-diode ladder region of a semiconductor device, the method comprising:

• forming a well region configured with a first dopant-type;
• forming active regions extending in a first direction including:
• forming alpha active regions configured with the first dopant-type to function as either cathodes or anodes of corresponding diodes, the forming alpha active regions including:
• locating a first alpha active region in the well region;
• forming beta active regions configured with a second dopant type different than the first dopant type to function complementarily as either anodes or cathodes of corresponding diodes, the forming beta active regions including:
• locating a first and second beta active regions in the well region;
• the first beta active region and a corresponding overlapping portion of the first alpha active region representing corresponding portions of a first diode;
• the second beta active region and a corresponding overlapping portion of the first alpha active region representing corresponding portions of a second diode;
• a second alpha active region and a corresponding overlapping portion of a third beta active region representing corresponding portions of a third diode;
• a third alpha active region and a corresponding overlapping portion of the third beta active region representing corresponding portions of a fourth diode;
• coupling the first alpha active region and the third beta active region correspondingly to different first and second reference voltages;
• coupling the first beta active region and the second alpha active region to a first node;
• coupling the second beta active region or the third alpha active region to a second node;
• and
• coupling a first resistor between the first node and the second node.

A resistor-diode ladder region of a semiconductor device comprising:

• alpha active regions extending in a first direction and being configured with a first dopant-type to function as either cathodes or anodes of corresponding diodes;
• and
• beta active regions extending in the first direction and being configured with a second dopant type different than the first dopant type to function complementarily as either anodes or cathodes of corresponding diodes;
• and
• a well region configured with the first dopant-type;
• a first alpha active region and first and second beta active regions being in the well region;
• the first beta active region and a corresponding overlapping portion of the first alpha active region representing corresponding portions of a first diode;
• the second beta active region and a corresponding overlapping portion of the first alpha active region representing corresponding portions of a second diode;
• a second alpha active region and a corresponding overlapping portion of a third beta active region representing corresponding portions of a third diode;
• a third alpha active region and a corresponding overlapping portion of the third beta active region representing corresponding portions of a fourth diode;
• the first alpha active region and the third beta active region being coupled correspondingly to different first and second reference voltages;
• the first beta active region and the second alpha active region being coupled to a first node;
• the second beta active region or the third alpha active region being coupled to a second node;
• and
• a first resistor coupling the first node to the second node.