Semiconductor device with a semiconductor body and method for producing it

• US 7,923,772 B2
• Filed: 04/30/2008
• Issued: 04/12/2011
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Schulze, Hans-Joachim, Mauder, Anton
• Primary Examiner(s): NGUYEN, NIKI HOANG
• Assistant Examiner(s): Nguyen; Tram H
• Application Number:
  US12/112,710
• Publication Number:
  US 20080265315A1
• Time in Patent Office: 1,077 Days
• Field of Search: 257/330, 257/259, 257/270, 257/271, 257/589, 257/E27.091, 257/E27.095, 257/E29.2, 257/E29.201, 257/E29.257, 257/E29.26, 257/214, 257/216, 257/302, 257/328, 257/331, 257/E27.052, 257/E27.079, 257E29036-E29038, 257E29046-E29225, 257/E21.388, 438/197, 438/268, 438/270
• US Class Current: 257/330
• CPC Class Codes: H01L 29/0611 for increasing or controlling the breakdown voltage of reverse biased devices H01L29/0661 takes precedence
• CPC Class Codes: H01L 29/0619 with a supplementary region doped oppositely to or in rectifying contact with the semiconductor containing or contacting region, e.g. guard rings with PN or Schottky junction
• CPC Class Codes: H01L 29/0623 Buried supplementary region, e.g. buried guard ring multi-RESURF H01L29/0634
• CPC Class Codes: H01L 29/0878 Impurity concentration or distribution
• CPC Class Codes: H01L 29/1095 Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/7397 and a gate structure lying on a slanted or vertical surface or formed in a groove, e.g. trench gate IGBT
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236

Abstract

A semiconductor device with a semiconductor body and to a method for producing it. In one embodiment, the semiconductor body has first electrodes which contact first highly doped semiconductor zones and complementary-conduction body zones surrounding the first semiconductor zones. The semiconductor body has a second electrode which contacts a second highly doped semiconductor zone. Between the second semiconductor zone and the body zones, a drift zone is arranged. Control electrodes which are insulated from the semiconductor body by a gate oxide and act on the body zones for controlling the semiconductor device are arranged on the semiconductor body. The body zones have minority charge carrier injector zones with complementary conduction to the body zones, arranged between the first semiconductor zones and the drift zone.

Claims

1. A semiconductor device with a semiconductor body, comprising:

first electrodes which contact first highly doped semiconductor zones and complementary-conduction body zones surrounding the first semiconductor zones;

a second electrode which contacts a second highly doped semiconductor zone;

a drift zone which is arranged between the body zones and the second semiconductor zone in the semiconductor body;

control electrodes which are insulated from the semiconductor body by a gate oxide and act on the body zones for controlling the semiconductor device; and

minority charge carrier injector zones situated within the body zones with complementary conduction to the body zones, arranged between the first semiconductor zones and the drift zone.

2. The semiconductor device of claim 1, wherein the injection zones are oriented within the body zones in such a manner that they have an upper planar first pn junction in the direction of the first electrode and a lower planar second pn junction in the direction of the drift zone and the second electrode.

3. The semiconductor device of claim 1, wherein the injector zones are arranged in manner that they are surrounded by the material of the body zones or that they are island-shaped or strip-shaped or are shaped as polygons in a normal doped manner or a complementary doped manner.

4. The semiconductor device of claim 1, wherein the body zones have differently doped areas, wherein first body zone areas which are contacted by the material of the first electrodes are doped more highly than second body zone areas surrounding them, which form the pn transitions to the drift zone and contact the gate oxide.

5. The semiconductor device of claim 4, wherein the injection zones within the body zones are configured such that they are surrounded by the material of the second body zone area or that the injection zones exhibit with their top sides pn transitions to the material of the first body zone areas (and with the undersides pn transitions to the material of the second body zone areas or that the injection zones exhibit with their top sides pn transitions to a third body zone area which has a lower dopant concentration than the second body zone area and which is arranged between the injection zones and the first electrodes or that the injection zones within the body zones are arranged in such a manner that their top sides contact the first electrodes and their undersides exhibit a pn junction with the second body zone area.

6. The semiconductor device of claim 1, wherein, for the body zone area below the underside of the injection zones, the following relation:

fN_Adz≈

Q_BR

with Q_BR breakdown charge of the semiconductor material,

z spatial coordinate in the direction of the field strength and

N_A dopant concentration in the second body zone area is met.

7. The semiconductor device of claim 1, wherein the extent w_v of the injector zone in the vertical direction in micrometers exhibits between 0.5 μ

m≦

w_v≦

10 μ

m with an integrated dopant dose C_D between 1·

10¹² cm<sup>−

2</sup>≦

C_D≦

1·

10¹⁶ cm<sup>−

2</sup> or between 5·

10¹² cm<sup>−

2</sup>≦

C_D≦

5·

10¹⁴ cm<sup>−

2</sup>.

8. The semiconductor device of claim 1, wherein the extent w₁ of the injector zones in the lateral direction in micrometers exhibits between 1 μ

m≦

w₁≦

300 μ

m or between 10 μ

m≦

w₁≦

200 μ

m.

9. The semiconductor device of claim 1, wherein the control electrodes are arranged as trench gate electrodes in trench structures, wherein the trench walls of the trench structures exhibit a gate oxide and a gate electrode material at least in the area of the body zone and wherein the trench structures exhibit further electrodes below the gate electrode material.

10. The semiconductor device of claim 1, wherein minority charge carrier injector zones with complementary doping to the drift zone are arranged at the transition or in the vicinity of the transition of the drift zone to the second semiconductor zone or they are arranged in such a manner that they form a pn junction both with the drift zone and with the second semiconductor zone, wherein the extent w_v of the injector zone in the vertical direction in micrometers exhibits between 0.1 μ

m≦

w_v≦

10 μ

m with an integrated dopant dose C_D between 1·

10¹² cm<sup>−

2</sup>≦

C_D≦

1·

10¹⁶ cm<sup>−

2</sup> or between 5·

10¹² cm<sup>−

2</sup>≦

C_D≦

5·

10¹⁴ cm<sup>−

2</sup>.

11. The semiconductor device of claim 1, wherein the injector zones are arranged in a field stop zone or below the trench gate electrodes in the drift zone or offset to the trench gate electrodes.

12. The semiconductor of claim 1, wherein the semiconductor device has as control electrodes trench gate electrodes which protrude into the drift zone, wherein further electrodes are arranged in the trench structures below the trench gate electrodes and wherein minority charge carrier injector zones with complementary conduction to the drift zone are arranged in the drift zone material between the trench structure and the second semiconductor zones.

13. The semiconductor device of claim 1, wherein the semiconductor device is a compensation semiconductor device with charge compensation zones extending vertically and doped complementarily to the drift zone, and wherein the charge compensation zones in the drift zones are arranged to be column shaped or trench shaped.

14. The semiconductor device of claim 1, wherein the semiconductor device has as control electrodes trench gate electrodes which protrude into the drift zone, wherein in the trench structures of the trenches, further electrodes are arranged below the trench gate electrodes and wherein a weakly doped pedestal area of the same type of conduction and having a weaker dopant concentration than the drift zone, which has minority charge carrier injector zones with complementary conduction to the drift zone, is arranged between the drift zone and the second semiconductor zones, wherein the injector zones are oriented in such a manner that they have, within the weakly doped pedestal area, planar first pn junctions in the direction of the first electrodes and planar second pn junctions in the direction of the second electrode.

15. The semiconductor device of claim 14, wherein the injector zones within the weakly doped pedestal area are arranged in such a manner that they are surrounded by the material of the pedestal area or are arranged vertically below the trench structures or are arranged laterally offset and below the trench structures.

16. The semiconductor device of claim 15, wherein the injector zones protrude into the second semiconductor zone from the pedestal area and wherein the injector zones have first pn junctions with the material of the weakly doped pedestal area and second pn junctions with the material of the second semiconductor zone.

17. The semiconductor device of claim 14, wherein charge carrier compensation structures in the drift zone of the power MOSFET are formed by vertical field plates or by zones extending vertically and doped complementarily to the drift zone.

18. The semiconductor of claim 1, wherein the semiconductor device is a power MOSFET and has injector zones in the body zone material or injector zones in the drift zone material or has injector zones both in the body zone material and in the drift zone material.

23. The semiconductor device of claim 1, wherein the body zone comprises doping material for p-conducting regions in Si which exhibits at least an energy level of 70 mev above the valence band border like Ga or In or wherein the low doped pedestal area comprises doping material for n-conducting regions in Si which exhibits an energy level of at least 150 mev below the conduction band border like S or Se.

24. A method of making a semiconductor device with a semiconductor body according to claim 1, comprising

contacting first electrodes with first highly doped semiconductor zones and complementary-conduction body zones surrounding the first semiconductor zones;

contacting a second electrode with a second highly doped semiconductor zone;

arranging a drift zone between the body zones and the second semiconductor zone in the semiconductor body;

insulating control electrodes from the semiconductor body by a gate oxide and act on the body zones for controlling the semiconductor device; and

wherein the body zones comprise minority charge carrier injector zones with complementary conduction to the body zones, arranged between the first semiconductor zones and the drift zone.

19. A semiconductor device with a semiconductor body, comprising:

first electrodes which contact first highly doped semiconductor zones and complementary-conduction body zones surrounding the first semiconductor zones;

a second electrode which contacts a second highly doped semiconductor zone;

a drift zone which is arranged between the body zones and the second semiconductor zone in the semiconductor body;

control electrodes which are insulated from the semiconductor body by a gate oxide and act on the body zones for controlling the semiconductor device;

minority charge carrier injector zones situated within the body zones with complementary conduction to the body zones, arranged between the first semiconductor zones and the drift zone; and

wherein a pedestal area doped more weakly than the drift zone, of the same conduction type as the drift zone, which has minority charge carrier injector zones of complementary conduction, is arranged between the drift zone and the second semiconductor zone.

20. The semiconductor of claim 19, wherein the minority charge carrier injector zones are oriented in such a manner that they have within the weakly doped pedestal area planar first pn junctions in the direction of the first electrode and planar second pn junctions in the direction of the second electrode, wherein the minority charge carrier injector zones within the weakly doped pedestal area are arranged in such a manner that they are surrounded by the material of the pedestal area or that they form a pn junction both with the pedestal area and with the second semiconductor zone or that they are arranged offset to the trench gate electrodes.

21. A semiconductor device with a semiconductor body, comprising:

first electrodes which contact first highly doped semiconductor zones and complementary-conduction body zones surrounding the first semiconductor zones;

a second electrode which contacts a second highly doped semiconductor zone;

a drift zone which is arranged between the body zones and the second semiconductor zone in the semiconductor body;

control electrodes which are insulated from the semiconductor body by a gate oxide and act on the body zones for controlling the semiconductor device;

wherein the body zones comprise minority charge carrier injector zones with complementary conduction to the body zones, arranged between the first semiconductor zones and the drift zone; and

wherein the injector zones are oriented in such a manner that they have within the drift zone material planar first pn junctions on their top sides in the direction of the trench structures and planar second pn junctions on their undersides in the direction of the second electrode, and wherein the injector zones are surrounded by the drift zone material of the drift zone or are arranged below the trench structures or are arranged below and offset to the trench structures.

22. The semiconductor device of claim 21, wherein the injector zones protrude into the second semiconductor zone from the drift zone, and wherein the injector zones have first pn junctions with the material of the drift zone and second pn junctions with the material of the second semiconductor zone.