Bipolar transistor with emitter and/or collector contact structure forming a Schottky contact and method of production
View Patent ↗A base contact connection, an emitter structure and a collector structure are arranged on an n-layer, which can be provided for additional npn transistors. The collector structure is arranged laterally to the emitter structure and at least one of the emitter and collector comprises a Schottky contact on a surface area of the n-layer.
1. A bipolar transistor, comprising:
an n-layer having a surface,
a base contact connection electrically conductively connected to the n-layer,
an emitter structure,
an emitter contact connection, which is a metal, electrically conductively connected to the emitter structure,
a collector structure arranged laterally to the emitter structure with respect to the surface of the n-layer, and
a collector contact connection, which is a metal, electrically conductively connected to the collector structure,
wherein at least one of the emitter contact connection and/or the collector contact connection forms a Schottky contact on the surface of the n-layer.
2. The bipolar transistor of claim 1 , wherein the emitter structure comprises a p + -layer that is arranged on the surface of the n-layer, and the collector contact connection forms a collector Schottky contact on the surface of the n- layer.
3. The bipolar transistor of claim 2 , further comprising an emitter contact layer, which is a metal, forming an ohmic contact on the p + -layer, the emitter contact layer carrying the emitter contact connection.
4. The bipolar transistor of claim 1 , wherein the emitter contact connection forms an emitter Schottky contact on the surface of the n- layer, and the collector structure comprises a p + -layer that is arranged on the surface of the n-layer.
5. The bipolar transistor of claim 4 , further comprising a collector contact layer, which is a metal, forming an ohmic contact on the p + -layer, the collector contact layer carrying the collector contact connection.
6. The bipolar transistor of claim 1 , wherein the emitter contact connection forms an emitter Schottky contact on the surface of the n- layer and the collector contact connection forms a collector Schottky contact on the surface of the n- layer.
7. The bipolar transistor of claim 1 , further comprising:
a substrate having a surface, and
an n + -region at the surface of the substrate, the n- layer being arranged on the n + -region,
wherein the base contact connection is arranged above an area of the n + -region that is not covered by the n-layer.
8. The bipolar transistor of claim 7 , further comprising a base contact layer, which is a metal, forming an ohmic contact on the n + -region, the base contact connection being arranged on the base contact layer.
9. The bipolar transistor of claim 1 , wherein the n-layer is part of a mesa.
10. The bipolar transistor of claim 1 , further comprising a substrate, the bipolar transistor and a vertical npn bipolar transistor being arranged on the substrate, the n-layer also being provided for a collector layer of the npn bipolar transistor.
11. A method of forming a bipolar transistor with an n-type base, the method comprising:
forming an n-layer of semiconductor material,
forming an emitter structure on the n-layer by either a) forming a p + -layer on the n-layer, and forming a metal emitter contact layer on the p + -layer or b) forming a metal emitter contact connection on the n-layer, and forming an emitter Schottky contact on the n-layer, and
forming a collector structure on the n-layer by either a) forming a p + -layer on the n-layer, and forming a metal collector contact layer on the p + -layer or b) forming a metal collector contact connection on the n-layer, and forming a collector Schottky contact on the n-layer,
wherein at least one of the emitter contact connection and/or the collector contact connection form a Schottky contact on an area of the surface of the n-layer.
12. A method of forming a bipolar transistor, the method comprising:
forming an n + -region,
forming an n-layer on the n 30 -region,
forming a p + -layer on the n-layer,
forming an emitter contact layer on the p + -layer,
forming a base contact layer on the n + -region,
forming a metal emitter contact connection on the emitter contact layer,
applying a metal base contact connection on the base contact layer, and
applying a metal collector contact connection on the n-layer, the collector contact connection forming a collector Schottky contact on the n-layer.
13. The method of claim 12 , wherein the emitter contact layer and the base contact layer are formed from a metal.
14. The method of claim 12 , further comprising forming an additional npn bipolar transistor, in which the n + -region forms a subcollector layer, the n-layer forms a collector layer, and the p + -layer forms a base layer.
15. The method of claim 11 , wherein forming the emitter structure comprises forming the p + -layer on the n-layer and forming the metal emitter contact layer on the p + -layer and wherein forming the collector structure comprises forming the p + -layer on the n-layer and forming the metal collector contact layer on the p + -layer.
16. The method of claim 11 , wherein forming the emitter structure comprises forming the metal emitter contact connection on the n-layer and forming the emitter Schottky contact on the n-layer, and wherein forming the collector structure comprises forming the metal collector contact connection on the n-layer and forming the collector Schottky contact on the n-layer.