Method for manufacturing a well isolation bipolar transistor
AssigneeSGS-Thomson Microelectronics S.A.
InventorYvon Gris
Life of this patent
Estimating the term…
Abstract
The present invention relates to an integrated circuit including a lateral well isolation bipolar transistor. A first portion of the upper internal periphery of the insulating well is hollowed and filled with polysilicon having the same conductivity type as the transistor base, to form a base contacting region. A second portion of the upper internal periphery of the insulating well is hollowed and filled with polysilicon having the same conductivity type as the transistor emitter, to form an emitter contacting region.
Claims18
A method for manufacturing a bipolar transistor, comprising the steps of:
- forming an island of an epitaxied layer of a first conductivity type surrounded with a well filled with insulator,
- etching a first portion of an upper internal periphery of the well to form a first hollowed portion,
- filling the first hollowed portion with polysilicon of a second conductivity type,
- performing a base implant of the second conductivity type,
- etching a second portion of the upper internal periphery of the well to form a second hollowed portion, and
- filling the second hollowed portion with polysilicon of the first conductivity type.
A method for manufacturing an integrated bipolar transistor having a collector, a base, and an emitter, the method comprising the steps of:
- forming an island of a first conductivity in an insulator such that the insulator surrounds said island at least on its sides;
- implanting a dopant of the second conductivity along a top surface of the island to form a first region of second conductivity in the island, said first region of second conductivity being distinct from a second region of first conductivity in the island
- etching a first portion of the insulator adjacent a first side region of the island to form a first hollowed portion;
- etching a second portion of the insulator adjacent a second side region of the island to form a second hollowed portion, said second hollowed portion being separated from said first hollowed portion by said insulator;
- and
- filling the first hollowed portion with a first polysilicon having a second conductivity;
- and
- filling the second hollowed portion with a second polysilicon having the first conductivity.
A method of forming a bipolar transistor, comprising the steps of:
- forming an island of first conductivity surrounded by an insulating material;
- doping said island to form a region of second conductivity on said island;
- formiing a first conductive layer of the second conductivity adjacent said island at a first peripheral region;
- forming a second conductive layer of the first conductivity adjacent said island at a second peripheral region distinct from said first peripheral region;
- and
- annealing said island, said first conductive layer, and said second conductive layer to form a first contact region on said island adjacent said first conductive layer and having said second conductivity, and a second contact region on said island adjacent said second conductive layer and having said first conductivity;
- wherein said second contact region of first conductivity is separated from said island of first conductivity by at least a portion of said region of second conductivity.
Dependencies are inferred from the claim text.