Integrated circuit with IGFETs - has highly doped ohmic contact surrounded by low doped second conductivity region within one IGFET zone

摘要

The semiconductor substrate of the integrated circuit has at least one region of first conductivity and at least two zones of second conductivity, surrounding each other at a distance. On the substrate surface and insulating zone is provided between the conductive zones and is coated with a conductive zone. An ohmic contact (32, 38) is highly doped and is surrounded of a lowly doped region (42) of the second conductivity within one zone of the pair (26). The lowly doped region (42) has preferably a surface resistance of at least 1 kOhm. The highly doped contact on the other hand has a surface resistance not exceeding 50 ohms.