Integrated device with bipolar transistor and electronic switch in “emitter switching” configuration
AssigneeSTMicroelectronics S.r.l.
InventorsSalvatore Leonardi, Davide Patti, Delfo Sanfilippo
Life of this patent
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Abstract
The integrated circuit device has a vertical conduction structure in which a region, which contains the base of a bipolar transistor, has zones having different concentrations. The concentrations are lower where the flow of charges is more intense and higher elsewhere. A high gain of the bipolar transistor and a low resistance of the electronic switch in conduction are thus obtained.
Claims19
A semiconductor device including a bipolar transistor and an electronic switch which are connected in an emitter switching configuration, the device comprising:
- a substrate;
- an epitaxial layer, having a first type of conductivity, on the substrate and containing at least part of a collector region of the bipolar transistor;
- a base region of the bipolar transistor, having a second type of conductivity, and buried in the epitaxial layer, the base region comprising a plurality of zones having different concentrations of doping impurities arranged in a direction parallel to a front surface of the device;
- a contact region, having the second type of conductivity, which extends in the epitaxial layer from the front surface of the device to the base region;
- a first active region of the electronic switch comprising an insulated region having the first type of conductivity and being delimited by the contact region, the first active region being above and in direct contact with the plurality of zones of the base region;
- a second active region of the electronic switch, having the second type of conductivity, and extending from the front surface of the device into the insulated region;
- and
- a third active region of the electronic switch, having the first type of conductivity, and extending from the front surface of the device into the second active region.
A semiconductor device including a bipolar transistor and an electronic switch which are connected in an emitter switching configuration, the device comprising:
- a substrate having a relatively high concentration of doping impurities;
- an epitaxial layer, having a first type of conductivity with a relatively low concentration of doping impurities, on the substrate and containing at least part of a collector region of the bipolar transistor;
- a first device terminal contacting the substrate;
- a base region of the bipolar transistor, having a second type of conductivity with a relatively low concentration of doping impurities, and buried in the epitaxial layer, the base region comprising a plurality of zones having different concentrations of doping impurities arranged in a direction parallel to a front surface of the device;
- a contact region, having the second type of conductivity with a relatively high concentration of doping impurities, which extends in the epitaxial layer from the front surface of the device to the base region;
- a first active region of the electronic switch comprising an insulated region having the first type of conductivity and being delimited by the contact region, the first active region being above and in direct contact with the plurality of zones of the base region;
- a second active region of the electronic switch, having the second type of conductivity, and extending from the front surface of the device into the insulated region;
- a third active region of the electronic switch, having the first type of conductivity with a relatively high concentration of doping impurities, and extending from the front surface of the device into the second active region;
- a second device terminal contacting the base region via the contact region;
- a third device terminal contacting the third active region of the electronic switch;
- and
- a fourth device terminal adjacent to the second active region of the electronic switch.
Dependencies are inferred from the claim text.