NPN equivalent structure with breakdown voltage greater than the intrinsic breakdown voltage of NPN transistors

Claim 2

A NPN equivalent transistor comprising a NPN transistor and a PNP transistor connected together through the respective collectors and a junction type, field effect transistor with grounded gate having the source connected to said collectors and the drain connected to the base of the PNP transistor; the base terminal of the NPN equivalent transistor corresponding to the base of said NPN transistor; the emitter terminal of said NPN equivalent transistor corresponding to the emitter of said NPN transistor; and the collector terminal of said NPN equivalent transistor corresponding to the emitter of said PNP transistor.

Claim 3

A semiconductor device comprising a plurality of circuital elements formed on a single monocrystalline semiconductor substrate, characterized by comprising a NPN equivalent structure constituted by a NPN transistor and a PNP transistor with isolated collector connected together through the respective collectors and by a junction type, field effect transistor with grounded gate having the source connected to said collectors and the drain connected to the base of the PNP transistor; the base terminal of the NPN equivalent structure corresponding to the base of said NPN transistor; the emitter terminal of said NPN equivalent structure corresponding to the emitter of said NPN transistor; and the collector terminal of said NPN equivalent structure corresponding to the emitter of said PNP transistor.

Claim 4

A semiconductor device comprising a plurality of circuital elements formed on a single monocrystalline semiconductor substrate, characterized by comprising a NPN equivalent structure constituted by a NPN transistor and a PNP transistor with isolated collector connected together through the respective collectors and by a junction type, field effect transistor with grounded gate having the source connected to said collectors and the drain connected to the base of the PNP transistor; the base terminal of the NPN equivalent structure corresponding to the base of said NPN transistor; the emitter terminal of said NPN equivalent structure corresponding to the emitter of said NPN transistor; and the collector terminal of said NPN equivalent structure corresponding to the emitter of said PNP transistor.

Claim 5

A semiconductor structure constituting a NPN equivalent transistor according to claim 2, and comprising a monocrystalline p silicon substrate connected to ground and a n silicon epitaxial layer wherein a vertical structure NPN transistor and a vertical structure PNP transistor with isolated collector are formed inside respective tubs defined by isolation regions of heavily doped p + silicon extending through the whole thickness of said epitaxial layer, and characterized in that, inside the tub containing the structure of said NPN transistor and outside a n + silicon contact region of the collector of said NPN transistor representing the source of said junction type, field effect transistor, is formed a p + silicon region, obtained by deep diffusion, which extends from the surface of the epitaxial layer toward the substrate for a depth corresponding to at least half of the thickness of said epitaxial layer, and is connected to ground, a n + diffusion, constituting the drain of said junction type, field effect transistor, is formed in a location adjacent to said deep p + diffusion, on the opposite side of that of said n + contact region, constituting the source of said junction type, field effect transistor, the gate of which is constituted by said deep p + diffusion and by the substrate itself both being connected to ground; an electrical path connects said n + contact region of the collector of the NPN transistor and of source of the field effect transistor with the collector of said PNP transistor; and another electrical path connects said drain of the field effect transistor to the base of said PNP transistor.