Method of making BiCMOS circuit
AssigneeMotorola, Inc.
InventorsJuergen Foerstner, Myriam Combes, Arlette Marty-Blavier, Guy Hautekiet
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Abstract
A method of manufacturing an integrated circuit having a buried layer of a low doped type of conductivity (2) and a buried layer of a highly doped type of the same conductivity (3) by masking a substrate (1) so as to define open areas on the substrate where it is desired to provide the two buried layers and doping the open areas of the substrate with a low concentration of dopants to form the low doped type of buried layer (2) is formed. Then one open area where the low doped type of buried layer (2) is formed is masked and the other open area is doped with a high concentration of dopants to form the highly doped type of buried layer (3).
Claims8
A method of manufacturing an integrated circuit having at least one lightly doped buried layer of one of a first conductivity type or a second conductivity type and at least one heavily doped buried layer of the one of the first conductivity type or the second conductivity type, the method comprising the steps of:
- providing a substrate;
- forming a first doping mask on the substrate, wherein the first doping mask defines at least first and second openings on the substrate where the at least one lightly doped buried layer and the at least one heavily doped buried layer are to be formed;
- doping a first portion of the substrate through the first opening with a dopant of a low concentration to form the lightly doped buried layer;
- forming a second doping mask on the first opening;
- doping a second portion of the substrate through the second opening with a high concentration of the dopant, whereby the heavily doped buried layer is formed;
- and
- removing the first and second doping masks from the substrate.
Dependencies are inferred from the claim text.