Integrated circuit comprising a device for protection against electrostatic discharge
AssigneeU.S. Philips Corporation
InventorClaude E. P. Chapron
Life of this patent
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Abstract
The protection device according to the invention is of the type comprising three active regions of alternating conductivity types, whose extreme regions are connected on the one hand to an input to be protected and on the other hand to a supply voltage source of the circuit. The first active region (2) forms a strip surrounded by the second active region (3). Contact regions (6 and 7) cover the active regions (2 and 3, respectively) and are covered by metallizations (8 and 9), respectively). The contact regions (6 and 7) are separated by thick insulating regions (4). One of the metallizations (8) is connected to the input to be protected and the other metallization (9) is connected to a reference voltage source.
Claims10
An integrated circuit having a protection device for protecting against electrostatic discharges comprising
- a semiconductor body having a substrate region of a first conductivity type, and an epitaxial layer of a second conductivity type,
- a protection device comprising at least one first active region and at least one second active region of said second conductivity type disposed in said substrate region, said first and second active regions being laterally spaced,
- a first conductive layer to be protected from electrostatic discharges and connected to said first active region,
- a second conductive layer connecting said second active region to a reference voltage source,
- said protection device further comprising at least one third active region formed by a portion of said substrate region and separating said first and said second active regions, said substrate region being more weakly dopend than said first and said second active regions, said first, third and second active regions forming at least three successive active regions of alternate conductivity types of said protection device,
- a first thick insulating layer having a thickness inset in said semiconductor body, said thickness extending to a first depth below a surface of said semiconductor body, said first thick insulating layer covering said third active region,
- wherein said first and said second active regions are disposed in said semiconductor body at a second depth below said surface greater than said first depth, and wherein each of said first and said second active regions have a first portion and a second portion, and
- a first contact region covering said first portion of said first active region and a second contact region covering said first portion of said second active region, said first and second contact regions forming part of said epitaxial layer and extending through the depth of said epitaxial layer,
- wherein said first conductive layer covers said first contact region and said second conductive layer covers said second contact region, and wherein said second portions of said first active region and said second active region are at least partly covered by said first thick insulating layer.
Dependencies are inferred from the claim text.