Power transistor with integrated temperature sensor element, power transistor circuit, method for operating a power transistor, and method for operating a power transistor circuit

Patent metadata

Field	Value
Publication number	US-9728580-B2
Application number	US-201313892600-A
Country	US
Kind code	B2
Filing date	May 13, 2013
Priority date	May 13, 2013
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A power transistor has a semiconductor body with a bottom side and top side spaced distant from the bottom side in a vertical direction. The semiconductor body includes a plurality of transistor cells, a source zone of a first conduction type, a body zone of a second conduction type, a drift zone of the first conduction type, a drain zone, and a temperature sensor diode having a pn-junction between an n-doped cathode zone and a p-doped anode zone. The power transistor also has a drain contact terminal on the top side, a source contact terminal on the bottom side, a gate contact terminal, and a temperature sense contact terminal on the top side. Depending on the first and second conduction types the anode or cathode zone is electrically connected to the source contact terminal and the other diode zone is electrically connected to the temperature sense contact terminal.

First claim

What is claimed is:

1. A power transistor, comprising:
a semiconductor body comprising:
a bottom side and a top side spaced distant from the bottom side in a vertical direction;
a plurality of transistor cells;
a source zone of a first conduction type;
a body zone of a second conduction type complementary to the first conduction type;
a drift zone of the first conduction type;
a drain zone;
a temperature sensor diode comprising a pn-junction formed between an n-doped cathode zone and a p-doped anode zone;
a first dielectric section extending from the bottom side to the top side, the first dielectric section being arranged between the cathode zone on one side and both the drift zone and the drain zone on another side;

a drain contact terminal arranged on the top side;
a source contact terminal arranged on the bottom side;
a gate contact terminal; and
a temperature sense contact terminal arranged on the top side and dielectrically insulated from the drain contact terminal;
wherein either
(I) the first conduction type is ‘n’ and the second conduction type is ‘p’, the anode zone is electrically connected to the source contact terminal, and the cathode zone is electrically connected to the temperature sense contact terminal; or
(II) the first conduction type is ‘p’ and the second conduction type is ‘n’, the cathode zone is electrically connected to the source contact terminal, and the anode zone is electrically connected to the temperature sense contact terminal.

2. The power transistor as claimed in claim 1 , wherein a distance between the pn-junction and the bottom side is smaller than a distance between the pn-junction and the top side.

3. The power transistor as claimed in claim 1 , wherein the body zone comprises, in the vertical direction, a first doping profile, and wherein the anode zone comprises, in the vertical direction, a second doping profile identical to the first doping profile.

4. The power transistor as claimed in claim 1 , wherein the drift zone comprises, in the vertical direction, a first doping profile, and wherein a first sub-zone of the cathode zone comprises, in the vertical direction, a second doping profile identical to the first doping profile.

5. The power transistor as claimed in claim 1 , wherein the drain zone comprises, in the vertical direction, a first doping profile, and wherein a second sub-zone of the cathode zone comprises, in the vertical direction, a second doping profile identical to the first doping profile.

6. The power transistor as claimed in claim 1 , wherein the drain contact terminal is a continuous connected layer without through holes.

7. The power transistor as claimed in claim 1 , wherein the anode zone is completely overlaid by the drain contact terminal.

8. The power transistor as claimed in claim 1 , wherein the gate contact terminal is arranged on the top side.

9. The power transistor as claimed in claim 1 , wherein the temperature sensor diode is surrounded by a u-shaped dielectric well that completely insulates the temperature sensor diode from the source, body, drain and drift zones, the u-shaped dielectric well comprising the first dielectric section, a second dielectric section disposed on the top side, and a third dielectric section disposed on the bottom side between the first dielectric section and the source contact terminal.

10. A power transistor circuit, comprising:
(a) a power transistor comprising:
a semiconductor body comprising:
a bottom side and a top side spaced distant from the bottom side in a vertical direction;
a plurality of transistor cells;
a source zone of a first conduction type;
a body zone of a second conduction type complementary to the first conduction type;
a drift zone of the first conduction type;
a drain zone;
a temperature sensor diode comprising a pn-junction formed between an n-doped cathode zone and a p-doped anode zone;
a first dielectric section extending from the bottom side to the top side, the first dielectric section being arranged between the cathode zone on one side and both the drift zone and the drain zone on another side;

a drain contact terminal arranged on the top side;
a source contact terminal arranged on the bottom side;
a gate contact terminal; and
a temperature sense contact terminal arranged on the top side and dielectrically insulated from the drain contact terminal;
wherein either
(I) the first conduction type is ‘n’ and the second conduction type is ‘p’, the anode zone is electrically connected to the source contact terminal, and the cathode zone is electrically connected to the temperature sense contact terminal; or
(II) the first conduction type is ‘p’ and the second conduction type is ‘n’, the cathode zone is electrically connected to the source contact terminal, and the anode zone is electrically connected to the temperature sense contact terminal; and

(b) an evaluation unit configured to evaluate a temperature dependent voltage drop across the pn-junction, the evaluation unit comprising an input electrically connected to the temperature sense contact terminal.

11. The power transistor circuit as claimed in claim 10 , further comprising a current source electrically connected to a circuit node between the temperature sense contact terminal and the input of the evaluation unit.

12. The power transistor circuit as claimed in claim 11 , wherein the current source is a constant current source.

13. The power transistor circuit as claimed in claim 10 , further comprising:
a first supply potential electrically connected to the source contact terminal;
a second supply potential that is positive relative to the first supply potential;
a third supply potential electrically connected to the temperature sense contact terminal, the third supply potential being positive relative to the first supply potential;
an electric load electrically connected between the drain contact terminal and the second supply potential; and
a current source electrically connected between the third supply potential and the temperature sense contact terminal.

14. The power transistor circuit as claimed in claim 13 , further comprising a temperature evaluation unit comprising a first input electrically connected to the temperature sense contact terminal.

15. The power transistor circuit as claimed in claim 10 , further comprising:
a first supply potential;
a second supply potential;
a third supply potential that is positive relative to both the first and second supply potentials;
an electric load electrically connected between the source contact terminal and the first supply potential; and
a current source electrically connected between the temperature sense contact terminal and the second supply potential.

16. The power transistor circuit as claimed in claim 15 , further comprising a temperature evaluation unit comprising a first input electrically connected to the temperature sense contact terminal.

17. The power transistor circuit as claimed in claim 16 , further comprising a reference constant voltage source electrically connected between a second input of the temperature evaluation unit and the source contact terminal.

18. The power transistor circuit as claimed in claim 10 , further comprising:
a first supply potential electrically connected via a load to the source contact terminal;
a second supply potential that is positive relative to the first supply potential; and
a current source electrically connected between the temperature sense contact terminal and a gate contact terminal of the power transisto

Assignees

• Infineon Technologies Ag

Inventors

• Meiser Andreas
• Thiele Steffen

Classifications

• G01K7/01 Primary

  using semiconducting elements having PN junctions (G01K7/02, G01K7/16, G01K7/30 take precedence) · CPC title

• H01L27/16 Primary

  Electricity · mapped topic

• H10N19/00 Primary

  Integrated devices, or assemblies of multiple devices, comprising at least one thermoelectric or thermomagnetic element covered by groups H10N10/00 - H10N15/00 · CPC title