Patent ID: 11876144
Assignee: VISHAY SEMICONDUCTOR GMBH
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 1:
2. A method of forming a photosensitive semiconductor component, the method comprising:
(i) providing a semiconductor substrate of a first conductivity type as a collector layer;
(ii) forming a less doped layer of the first conductivity type above the semiconductor substrate, wherein
a first region of the less doped layer of a first thickness that is smaller than a first threshold value is formed on or in a first region of the substrate,
a second region of the less doped layer of a second thickness that is higher than a second threshold value that is higher than the first threshold value is formed on or in a second region of the semiconductor substrate,
wherein the first region and the second region are adjacent to one another on or in the semiconductor substrate, or include a transition region between them on or in the semiconductor substrate on, or in which transition region a transition region of the less doped layer is formed, and
wherein a doping concentration in the less doped layer is set as smaller than that of the semiconductor substrate;

(iii) forming a semiconductor base layer of a second conductivity type therein or thereabove wherein said semiconductor base layer of the second conductivity type is formed such that it has a first base layer region above at least a part of the first region of the less doped layer, a second base layer region above at least a part of the second region of the less doped layer, and a transition base layer region above at least a part of the transition region of the less doped layer; and
(iv) forming an emitter layer of the first conductivity type therein or thereabove, such that a part of the base layer is not covered by the emitter layer, wherein said emitter layer of the first conductivity type is formed on or in the second base layer region such that at least a part of the first base layer region is not covered by the emitter layer;
wherein at least one of the less doped layer or the semiconductor base layer is formed with regions of different thickness, and thereafter the emitter layer is formed in a region having a greatest thickness of the at least one of the less doped layer or the semiconductor base layer.