Semiconductor switch with integrated temperature sensor

Patent metadata

Field	Value
Publication number	US-9735264-B2
Application number	US-201514840925-A
Country	US
Kind code	B2
Filing date	Aug 31, 2015
Priority date	Sep 5, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A semiconductor device includes a semiconductor body, at least one wiring layer disposed on the semiconductor body and a field effect transistor integrated in the semiconductor body. The field effect transistor has a plurality of gate electrodes residing in corresponding gate trenches formed in the semiconductor body. A first circuit is integrated in the semiconductor body adjacent to the field effect transistor, and a second circuit is integrated in the semiconductor body remote from the first circuit. A first additional trench is formed in the semiconductor body and includes at least one connecting line which electrically connects the first circuit and the second circuit. The semiconductor device also includes at least one conductive pad formed in the at least one wiring layer. The at least one conductive pad is arranged to at least partially cover the first additional trench to form a shielding of the at least one connecting line.

First claim

What is claimed is:

1. A semiconductor device, comprising:
a semiconductor body;
at least one wiring layer disposed on the semiconductor body;
a field effect transistor integrated in the semiconductor body, the field effect transistor having a plurality of gate electrodes residing in corresponding gate trenches formed in the semiconductor body;
a temperature sensor integrated in the semiconductor body adjacent to the field effect transistor;
a temperature sense circuit integrated in the semiconductor body and remote from the temperature sensor;
a first additional trench formed in the semiconductor body, the first additional trench including at least one sense line which electrically connects the temperature sensor and the temperature sense circuit; and
at least one conductive pad formed in the at least one wiring layer, the at least one conductive pad being arranged to at least partially cover the first additional trench to form a shielding of the at least one sense line.

2. The semiconductor device of claim 1 , wherein two sense lines are arranged in the first additional trench.

3. The semiconductor device of claim 1 , further comprising a second additional trench in the semiconductor body, the second additional trench including at least one sense line which electrically connects the temperature sensor and the temperature sense circuit.

4. The semiconductor device of claim 3 , wherein the first and the second additional trenches each include a single sense line.

5. The semiconductor device of claim 1 , wherein the first additional trench includes an additional force line connecting the temperature sense circuit and the temperature sensor to supply the temperature sensor with a defined current.

6. The semiconductor device of claim 3 , wherein the first and the second additional trenches each include an additional force line connecting the temperature sense circuit and the temperature sensor to supply the temperature sensor with a defined current.

7. The semiconductor device of claim 6 , wherein the temperature sense circuit includes a stabilized constant current source for providing the defined current.

8. The semiconductor device of claim 1 , wherein the at least one sense line connects the temperature sense circuit with the temperature sensor to apply a voltage to or to sense a voltage at the temperature sensor.

9. The semiconductor device of claim 1 , further comprising a contact layer disposed on the semiconductor body so that a first wiring layer of the at least one wiring layer is between the contact layer and the semiconductor body, wherein the contact layer is electrically connected to a first load terminal of the field effect transistor.

10. The semiconductor device of claim 9 , wherein the at least one conductive pad, which forms the shielding, is electrically coupled connected to a second load terminal of the field effect transistor.

11. The semiconductor device of claim 1 , wherein the at least one conductive pad, which forms the shielding, is operationally coupled to a constant potential.

12. The semiconductor device of claim 1 , wherein the at least one conductive pad, which forms the shielding, is electrically coupled with the semiconductor body.

13. The semiconductor device of claim 5 , wherein the sense and the force lines are isolated from the surrounding semiconductor body by an insulation layer.

14. The semiconductor device of claim 13 , wherein the insulation layer has a variable thickness which depends on a position in the trench.

15. The semiconductor device of claim 1 , wherein the field effect transistor is composed of an array of transistor cells, each cell being associated with a gate electrode, wherein the first additional trench is routed through the array of transistor cells.

16. The semiconductor device of claim 1 , wherein the temperature sensor is a diode or a base-emitter diode of a bipolar transistor.

17. The semiconductor device of claim 9 , wherein the at least one wiring layer is interposed between the semiconductor body and the at least one conductive pad, wherein the at least one conductive pad is interposed between the at least one wiring layer and the contact layer, wherein the at least one conductive pad is separated from the at least one wiring layer by a first insulation layer, and wherein the at least one conductive pad is separated from the contact layer by a second insulation layer.

18. The semiconductor device of claim 9 , wherein the at least one conductive pad is connected to a constant voltage so as to inhibit capacitive coupling between the at least one sense line and the contact layer.

19. The semiconductor device of claim 16 , further comprising an additional sense line disposed in the same additional trench as the at least one sense line or in a different additional trench formed in the semiconductor body, wherein a base of the bipolar transistor is connected to a first one of the sense lines, and wherein an emitter of the bipolar transistor is connected to a second one of the sense lines.

Assignees

• Infineon Technologies Ag

Inventors

• Krischke Norbert
• Auer Bernhard
• Illing Robert

Classifications

• H01L29/7803 Primary

  Electricity · mapped topic

• H01L29/7815

  Electricity · mapped topic

• H01L29/7813

  Electricity · mapped topic

• H01L29/407

  Electricity · mapped topic

• H10D64/117

  Recessed field plates, e.g. trench field plates or buried field plates · CPC title