Method for manufacturing a bipolar junction transistor
Embodiments provide a method for manufacturing a bipolar junction transistor, comprising: providing a semiconductor substrate comprising a buried layer of a first conductive type; doping the semiconductor substrate in a collector implant region, to obtain a collector implant of the first conductive type extending parallel to a surface of the semiconductor substrate and from the surface of the semiconductor substrate to the buried layer; providing a base layer of a second conductive type on the surface of the semiconductor substrate, the base layer covering the collector implant; providing a sacrificial emitter structure on the base layer, wherein a projection of an area of the sacrificial emitter structure is enclosed by an area of the collector implant; and partially counter doping the collector implant through an area of the base layer surrounding an area of the base layer that is covered by the sacrificial emitter structure.
1. A bipolar transistor, comprising:
a collector of a first conductive type;
a base layer of a second conductive type arranged above the collector;
an emitter of the first conductive type arranged above the base layer,
the collector being self-aligned to the emitter;
an emitter isolation layer laterally surrounding the emitter; and
a base link laterally physically connected to the base layer and extending lateral to the base layer,
the base link being vertically connected to a portion of the base layer and extending above the base layer, and
the base link being laterally connected to the emitter isolation layer.
2. The bipolar transistor according to claim 1 , further comprising:
a stop layer on the emitter and the base link.
3. The bipolar transistor according to claim 2 , wherein the stop layer is a SiN layer.
4. The bipolar transistor according to claim 1 , further comprising:
an emitter contact contacting the emitter, and
base contacts contacting the base link.
5. The bipolar transistor according to claim 1 , wherein the emitter has zero overlap with the base link.
6. A method comprising:
providing a collector of a first conductive type;
arranging a base layer of a second conductive type above the collector;
providing an emitter of the first conductive type above the base layer,
the collector being self-aligned with the emitter;
surrounding the emitter with an emitter isolation layer; and
laterally physically connecting a base link to the base layer,
the base link extending lateral to the base layer,
the base link being vertically connected to a portion of the base layer and extending above the base layer, and
the base link being laterally connected to the emitter isolation layer.
7. The method according to claim 6 , wherein arranging the base layer comprises epitaxially growing the base layer on a surface of a semiconductor substrate at least in an area adjacent to the collector.
8. The method according to claim 6 , further comprising:
removing a sacrificial emitter to obtain an emitter window; and
where providing the emitter includes:
providing an emitter layer of the first conductive type in the emitter window to obtain the emitter.
9. The method according to claim 8 , wherein the emitter layer is provided such that an overfill of the emitter window is achieved.
10. The method according to claim 8 , wherein the emitter layer has a minimum thickness of 60 nm.
11. The method according to claim 8 , wherein the emitter layer has a width equal to 90 nm.
12. The method according to claim 8 , wherein providing the emitter includes:
partially removing the emitter layer to obtain the emitter in the emitter window.
13. The method according to claim 8 , wherein providing the emitter includes:
partially removing the emitter layer at least up to the base link to obtain the emitter in the emitter window.
14. The method according to claim 6 , further comprising:
providing a stop layer for contact hole etch on the emitter and the base link.
15. The method according to claim 14 , wherein the stop layer is a SiN layer.
16. The method according to claim 6 , further comprising:
providing base contacts contacting the base link.
17. The method according to claim 16 , wherein the base contacts are metal.
18. The method according to claim 6 , further comprising:
providing an emitter contact contacting the emitter.
19. The method according to claim 18 , wherein the emitter contact is metal.
20. The method according to claim 6 , wherein the emitter has zero overlap with the base link.