Integrated circuit comprising a gradually doped bipolar transistor and corresponding fabrication process
AssigneeSTMicroelectronics S.r.l.
InventorsDamien Lenoble, Thierry Schwartzmann, Laurence Boissonnet
Life of this patent
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Abstract
An integrated circuit includes a bipolar transistor comprising a substrate and a collector formed in the substrate. The collector includes a highly doped lateral zone, a very lightly doped central zone and a lightly doped intermediate zone located between the central zone and the lateral zone 4a of the collector. The substrate includes a lightly doped lateral zone and a highly doped central zone. The dopant species in the zone of the substrate are electrically inactive.
Claims24
1-9. (canceled)
A method for making an integrated circuit comprising:
- forming a collector of a bipolar transistor in an upper layer of a substrate by implanting at least one dopant species to form a highly doped lateral zone, a very lightly doped central zone and a lightly doped intermediate zone between the central zone and the lateral zone;
- and
- as a result of forming the collector, forming a lower layer of the substrate underlying the collector to have a lightly doped lateral zone and a highly doped central zone, with dopant species in the central zone being electrically inactive.
A method for making an integrated circuit comprising:
- forming a bipolar transistor comprising a collector in an upper layer of a substrate so that the collector has a highly doped lateral zone, a very lightly doped central zone and a lightly doped intermediate zone between the central zone and the lateral zone;
- and
- forming a lower layer of the substrate underlying the collector to have a lightly doped lateral zone and a highly doped central zone, with dopant in the central zone being electrically inactive.
A method for making an integrated circuit comprising:
- providing a silicon-on-insulator substrate comprising an insulator layer and a silicon layer thereon;
- and
- forming a bipolar transistor comprising a collector in the silicon layer so that the collector has a highly doped lateral zone, a very lightly doped central zone and a lightly doped intermediate zone between the central zone and the lateral zone;
- and with the insulating layer underlying the collector having a lightly doped lateral zone and a highly doped central zone, with dopant in the central zone being electrically inactive.
A method for making an integrated circuit comprising:
- providing a substrate comprising a lower layer and an upper layer thereon;
- and
- forming a bipolar transistor comprising a collector in the upper layer of the substrate, the collector comprising a lateral zone with a first dopant concentration, a central zone with a second dopant concentration and an intermediate zone with a third dopant concentration between the central zone and the lateral zone;
- and with the lower layer of the substrate comprising a lateral zone with a fourth dopant concentration and a central zone with a fifth dopant concentration, with dopant in the central zone being electrically inactive.
Dependencies are inferred from the claim text.