Process for fabricating a self-aligned vertical bipolar transistor
AssigneeSTMicroelectronics S.r.l.
InventorsAlain Chantre, Michel Marty, Helene Baudry
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Abstract
The fabrication process comprises a phase of producing a base region having an extrinsic base and an intrinsic base, and a phase of producing an emitter region comprising an emitter block having a narrower lower part located in an emitter window provided above the intrinsic base. Production of the extrinsic base comprises implantation of dopants, carried out after the emitter window has been defined, on either side of and at a predetermined distance dp from the lateral boundaries of the emitter window so as to be self-aligned with respect to this emitter window, and before the emitter block is formed.
Claims14
A process for fabricating a bipolar transistor comprising the steps of:
- producing a base region comprising an extrinsic base and an intrinsic base;
- producing an emitter region above the intrinsic base comprising an emitter block with a narrower lower part located in an emitter window, the emitter window produced with vertical lateral boundaries;
- and
- implanting dopants in the extrinsic base before the emitter block is formed and after the production of the emitter window, so that dopants are implanted on either side of and at a predetermined distance from the vertical lateral boundaries of the emitter window, so that the extrinsic base is self-aligned with respect to the emitter window.
The process according to claim 11, wherein the step of producing the emitter region includes producing the emitter region with epitaxial growth, on the emitter window, of the upper surface of the base stack so as to obtain, at least above the said window, an emitter region formed from monocrystalline silicon and directly in contact with the upper layer of the stack.
A bipolar transistor which comprises:
- a base region comprising an extrinsic base and an intrinsic base;
- an emitter region above the intrinsic base comprising an emitter block with a narrower lower part located in an emitter window, the emitter window produced with vertical lateral boundaries;
- and
- dopants implanted in the extrinsic base before the emitter block is formed and after the production of the emitter window, so that dopants are implanted on either side of and at a predetermined distance from the vertical lateral boundaries of the emitter window, so that the extrinsic base is self-aligned with respect to the emitter window.
Dependencies are inferred from the claim text.