Charge-compensation semiconductor device

• US 9,147,763 B2
• Filed: 09/23/2013
• Issued: 09/29/2015
• Est. Priority Date: 09/23/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Weber, Hans, Hirler, Franz, Willmeroth, Armin, Gamerith, Stefan
• Primary Examiner(s): Le, Thao X
• Assistant Examiner(s): REDDINGTON, PATRICIA D
• Application Number:
  US14/033,941
• Publication Number:
  US 20150084120A1
• Time in Patent Office: 736 Days
• Field of Search: 257/329
• US Class Current: 1/1
• 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 29/0634 Multiple reduced surface field (multi-RESURF) structures, e.g. double RESURF, charge compensation, cool, superjunction (SJ), 3D-RESURF, composite buffer (CB) structures
• CPC Class Codes: H01L 29/0638 for preventing surface leakage due to surface inversion layer, e.g. with channel stopper channel stoppers in combination with isolation region for integrated circuits H01L21/762
• 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 29/78 with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• CPC Class Codes: H01L 29/7804 the other device being a pn-junction diode
• CPC Class Codes: H01L 29/7808 the other device being a breakdown diode, e.g. Zener diode
• CPC Class Codes: H01L 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402

Abstract

An active area of a semiconductor body includes a first charge-compensation structure having spaced apart n-type pillar regions, and an n-type first field-stop region of a semiconductor material in Ohmic contact with a drain metallization and the n-type pillar regions and having a doping charge per area higher than a breakdown charge per area of the semiconductor material. A punch-through area of the semiconductor body includes a p-type semiconductor region in Ohmic contact with a source metallization, a floating p-type body region and an n-type second field-stop region. The floating p-type body region extends into the active area. The second field-stop region is in Ohmic contact with the first field-stop region, forms a pn-junction with the floating p-type body region, is arranged between the p-type semiconductor region and floating p-type body region, and has a doping charge per area lower than the breakdown charge per area of the semiconductor material.

Claims

1. A semiconductor device, comprising a semiconductor body comprising a main horizontal surface, an active area, a punch through area, a source metallization arranged on the main horizontal surface and a drain metallization, in the active area the semiconductor body further comprising in a vertical cross-section substantially orthogonal to the main horizontal surface:

a first charge-compensation structure comprising a plurality of spaced apart first n-type pillar regions; and

an n-type first field-stop region comprised of a semiconductor material, in Ohmic contact with the drain metallization and the first n-type pillar regions, and having a doping concentration per area higher than a breakdown charge per area of the semiconductor material divided by the elementary charge,

in the punch-through area the semiconductor body further comprising;

a p-type semiconductor region in Ohmic contact with the source metallization;

a floating p-type body region extending from the punch-through area into the active area; and

an n-type second field-stop region in Ohmic contact with the first field-stop region, forming a pn-junction with the floating p-type body region, arranged between the p-type semiconductor region and the floating p-type body region, and having a doping concentration per area lower than the breakdown charge per area of the semiconductor material divided by the elementary charge.

2. The semiconductor device of claim 1, wherein the first charge-compensation structure further comprises, in the vertical cross-section, first p-type pillar regions alternating with the first n-type pillar regions, wherein the first p-type pillar regions are in Ohmic contact with the source metallization, and wherein an integrated dopant concentration of the first n-type pillar regions substantially matches an integrated dopant concentration of the first p-type pillar regions.

3. The semiconductor device of claim 2, wherein the semiconductor body further comprises, in the vertical cross-section, a plurality of p-type body regions in Ohmic contact with the source metallization, wherein each of the p-type body regions is arranged on an adjoining one of the first p-type pillar regions and comprises a higher maximum doping concentration than the first p-type pillar regions.

4. The semiconductor device of claim 2, wherein the first n-type pillar regions and the first p-type pillar regions are substantially depletable at a reverse voltage applied between the source metallization and the drain metallization that is lower than a rated breakdown voltage of the semiconductor device.

5. The semiconductor device of claim 1, wherein the semiconductor body further comprises in the vertical cross-section at least one of:

a cathode region adjoining the second field-stop region, having a higher maximum doping concentration than at least one of the first field-stop region and the second field-stop region, and forming a pn-junction with the floating body region;

an edge delimiting the semiconductor body in a direction substantially parallel to the main horizontal surface;

a first semiconductor region having a first maximum doping concentration of n-type dopants lower than a maximum doping concentration of the first field-stop region, arranged at least in the punch-through area, adjoining the second field-stop region and substantially extending to the main horizontal surface and to the edge;

an n-type drain region forming an Ohmic contact with the drain metallization; and

a second charge-compensation structure arranged below the first charge-compensation structure and comprising a plurality of second n-type pillar regions adjoining the n-type first field-stop region and alternating with second p-type pillar regions adjoining the floating body region, wherein an integrated dopant concentration of the second n-type pillar regions substantially matches an integrated dopant concentration of the second p-type pillar regions.

6. The semiconductor device of claim 5, wherein the semiconductor body further comprises a peripheral area extending to the edge, and wherein the semiconductor device further comprises in the peripheral area at least one of:

an n-type channel-stop region adjoining the first semiconductor region, having a maximum doping concentration higher than the first maximum doping concentration and arranged at least close to the edge and/or the main horizontal surface;

an n-type third field-stop region in Ohmic contact with the first field-stop region, comprised of the semiconductor material and having a doping concentration per horizontal area higher than the breakdown charge per area of the semiconductor material divided by the elementary charge, wherein the second field-stop region is arranged between the third field-stop region and the first field-stop region;

an n-type first equipotential semiconductor region embedded in the first semiconductor region and extending from the third field-stop region substantially to the main horizontal surface;

a p-type second equipotential semiconductor region embedded in the first semiconductor region and extending from the floating body region substantially to the main horizontal surface;

a charge-generating structure arranged next to the main horizontal surface in Ohmic contact with at least one of the first equipotential semiconductor region and the second equipotential semiconductor region;

a metal layer arranged on the main horizontal surface and forming an abutting contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

a silicide layer arranged on the main horizontal surface and in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

a semiconductor region arranged at the main horizontal surface, in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region, and comprising at least one of lattice defects and deep traps;

a dielectric region arranged on the main horizontal surface and extending between the first equipotential semiconductor region and the second equipotential semiconductor region, wherein at least one of the first equipotential semiconductor region, the second equipotential semiconductor region and a portion of the first semiconductor region arranged therebetween comprises at least close to the dielectric region at least one of lattice defects and deep traps;

a diode structure arranged next to the main horizontal surface and in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

a transistor structure arranged next to the main horizontal surface and in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

an n-type first semiconductor layer extending to the edge, adjoining the first semiconductor region, having a maximum doping concentration higher than the first semiconductor region, and being in the active area arranged between the second charge-compensation structure and the drain metallization;

an n-type third equipotential semiconductor region embedded in the first semiconductor region and extending from the first semiconductor layer substantially to the main horizontal surface; and

an n-type drain layer extending to the edge, adjoining first semiconductor layer, having a maximum doping concentration higher than the first semiconductor layer, and forming an Ohmic contact with the drain metallization.

7. The semiconductor device of claim 5, wherein the first semiconductor region is substantially un-doped.

8. The semiconductor device of claim 1, wherein the doping concentration per area of the first field-stop region is at least about two times the breakdown charge per area of the semiconductor material divided by the elementary charge.

9. The semiconductor device of claim 1, wherein the floating body region is comprised of the semiconductor material and has a doping concentration per area higher than the breakdown charge per area of the semiconductor material divided by the elementary charge.

10. The semiconductor device of claim 1, wherein the first charge-compensation structure further comprises, in the vertical cross-section, trench field-electrodes alternating with the first n-type pillar regions, wherein each of the trench field-electrodes comprises a field-electrode in Ohmic contact with the source metallization and a field-dielectric region separating the field-electrode from adjacent first n-type pillar regions.

11. A semiconductor device, comprising a semiconductor body comprised of a semiconductor material having a breakdown charge per area, and comprising:

a drain region of a first conductivity type;

a plurality of spaced apart body regions of a second conductivity type;

a first charge-compensation structure arranged between the body regions and the drain region, and comprising, in a first cross-section, a plurality of spaced apart first pillar regions of the first conductivity type;

a second charge-compensation structure integrated in the semiconductor body, and comprising a plurality of spaced apart second pillar regions of the first conductivity type in Ohmic contact with the drain region;

a first field-stop region of the first conductivity type arranged between the first charge-compensation structure and the second charge-compensation structure, having a doping concentration per area higher than the breakdown charge per area of the semiconductor material divided by the elementary charge, and in Ohmic contact with the first pillar regions of the first conductivity type and the second pillar regions of the first conductivity type; and

a second field-stop region of the first conductivity type having a doping concentration per area lower than the breakdown charge per area of the semiconductor material divided by the elementary charge, and in Ohmic contact with the first pillar regions via the first field-stop region.

12. The semiconductor device of claim 11, wherein the first charge-compensation structure further comprises, in the first vertical cross-section, first pillar regions of the second conductivity type alternating with the first pillar regions of the first conductivity type, wherein each of the first pillar regions of the second conductivity type adjoins one of the body regions.

13. The semiconductor device of claim 11, wherein the second charge-compensation structure further comprises at least one of charge generation centers and in the first vertical cross-section, second pillar regions of the second conductivity type alternating with the second pillar regions of the first conductivity type, and wherein the floating body region adjoins at least one of the second pillar regions of the second conductivity type.

14. The semiconductor device of claim 11, wherein the second charge-compensation structure further comprises, in a second vertical cross-section substantially orthogonal to the first vertical cross-section, second pillar regions of the second conductivity type alternating with the second pillar regions of the first conductivity type, and wherein the floating body region adjoins at least one of the second pillar regions of the second conductivity type.

15. The semiconductor device of claim 11, wherein the semiconductor body further comprises an edge delimiting the semiconductor body in a direction substantially parallel to the first cross-section, an active area and a punch-through area arranged between the active area and the edge, wherein the first semiconductor region substantially extends to the edge, wherein the first charge-compensation structure, the second charge-compensation structure and the first field-stop region are arranged in the active area, wherein the second field-stop region is arranged in the punch-through area, and wherein the semiconductor body further comprises in the punch-through area at least one of:

a first semiconductor region having a first maximum doping concentration of dopants of the first conductivity type lower than a maximum doping concentration of the first field-stop region adjoining at least one of the first field-stop region and the second field-stop region;

a further body region of the second conductivity type in Ohmic contact with the body regions and forming a pn-junction with the first semiconductor region;

a floating body region of the second conductivity type adjoining at least one of the first field-stop region and the second field-stop region; and

a cathode region of the first conductivity type adjoining the second field-stop region, having a higher maximum doping concentration than at least one of the first field-stop region and the second field-stop region, and forming a pn-junction with the floating body region.

16. The semiconductor device of claim 15, wherein the semiconductor body further comprises a peripheral area extending to the edge, wherein the first semiconductor region substantially extends to at least one of the edge and a main horizontal surface of the semiconductor body which is substantially parallel to the first vertical cross-section, wherein the punch-through area is arranged between the active area and the peripheral area, and wherein the semiconductor device further comprises in the peripheral area at least one of:

a channel-stop region of the first conductivity type adjoining the first semiconductor region, having a maximum doping concentration higher than the first maximum doping concentration and arranged at least close to the edge and/or the main horizontal surface;

a third field-stop region of the first conductivity type in Ohmic contact with the first field-stop region, and having a doping concentration per horizontal area higher than the breakdown charge per area of the semiconductor material divided by the elementary charge, wherein the second field-stop region is arranged between the first field-stop region and the third field-stop region;

a first equipotential semiconductor region of the first conductivity type embedded in the first semiconductor region and extending from the third field-stop region substantially to the main horizontal surface;

a second equipotential semiconductor region of the second conductivity type embedded in the first semiconductor region and extending from the floating body region substantially to the main horizontal surface;

a first semiconductor layer extending to the edge, adjoining the first semiconductor region, having a maximum doping concentration higher than the first maximum doping concentration, and being in the active area arranged between the second charge-compensation structure and the drain metallization;

a third equipotential semiconductor region of the first conductivity type embedded in the first semiconductor region and extending from the first semiconductor layer substantially to the main horizontal surface;

a drain layer of the first conductivity type extending to the edge, adjoining first semiconductor layer, having a maximum doping concentration higher than the first semiconductor layer, and forming an Ohmic contact with the drain metallization;

a charge-generating structure arranged next to the main horizontal surface in Ohmic contact with at least one of the first equipotential semiconductor region and the second equipotential semiconductor region;

a metal layer arranged on the main horizontal surface and forming an abutting contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

a silicide layer arranged on the main horizontal surface and in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

a semiconductor region arranged on the main horizontal surface, in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region, and comprising at least one of lattice defects and deep traps;

a dielectric region arranged on the main horizontal surface and extending between the first equipotential semiconductor region and the second equipotential semiconductor region, wherein at least one of the first equipotential semiconductor region, the second equipotential semiconductor region and a portion of the first semiconductor region arranged between the first equipotential semiconductor region and the second equipotential semiconductor region comprises at least close to the dielectric region at least one of lattice defects and deep traps;

a diode structure arranged next to the main horizontal surface and in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region;

a transistor structure arranged next to the main horizontal surface and in Ohmic contact with the first equipotential semiconductor region and the second equipotential semiconductor region.

17. A semiconductor device, comprising a semiconductor body comprised of a semiconductor material having a breakdown charge per area and comprising a main horizontal surface, an active area, a punch through area, a source metallization arranged on the main horizontal surface and a drain metallization, in the active area the semiconductor body further comprising in a vertical cross-section substantially orthogonal to the main horizontal surface:

a first charge-compensation structure comprising a plurality of spaced apart first p-type pillar regions in Ohmic contact with the source metallization;

a second charge-compensation structure comprising a plurality of spaced apart second p-type pillar regions; and

an n-type first embedded field-stop region in Ohmic contact with the drain metallization arranged between the first p-type pillar regions and the second p-type pillar regions, and having a doping concentration per area higher than the breakdown charge per area of the semiconductor material divided by the elementary charge,

in the punch-through area the semiconductor body further comprising;

a first semiconductor region in Ohmic contact with the drain metallization;

a p-type semiconductor region in Ohmic contact with the source metallization and forming a pn-junction with the first semiconductor region;

a floating p-type body region extending from the punch-through area into the active area, having a higher maximum doping concentration than the second p-type pillar regions and adjoining each of the second p-type pillar regions; and

an n-type second embedded field-stop region in Ohmic contact with the first embedded field-stop region, forming a pn-junction with the floating p-type body region, arranged between the first semiconductor region and the floating p-type body region, and having a doping concentration per area lower than the breakdown charge per area of the semiconductor material divided by the elementary charge.

18. The semiconductor device of claim 17, wherein the first p-type pillar regions are substantially depletable at a reverse voltage applied between the source metallization and the drain metallization that is lower than a rated breakdown voltage of the semiconductor device.

19. A vertical semiconductor device, comprising a semiconductor body comprising a main horizontal surface and an edge delimiting the semiconductor body in a direction substantially parallel to the main horizontal surface, a first metallization arranged on the main horizontal surface, and a second metallization arranged opposite to the first metallization, the semiconductor body further comprising:

a first semiconductor region having a first maximum doping concentration in Ohmic contact with the second metallization, and substantially extending to at least one of the main horizontal surface and the edge;

an embedded field-stop zone of a first conductivity type in Ohmic contact with the first semiconductor region and the second metallization, having a maximum doping concentration higher than the first maximum doping concentration, and adjoining the first semiconductor region;

a second semiconductor region of a second conductivity type in Ohmic contact with the first metallization, arranged at least close to the main horizontal surface, forming a rectifying junction with the first semiconductor region, and overlapping with the embedded field-stop zone when viewed from above;

a floating body region of the second conductivity type arranged between the embedded field-stop zone and the second metallization, and forming a pn-junction with the embedded field-stop zone;

a first equipotential semiconductor region of the first conductivity type embedded in the first semiconductor region, extending from the embedded field-stop region substantially to the main horizontal surface, and arranged between the second semiconductor region and the edge; and

a second equipotential semiconductor region of the second conductivity type embedded in the first semiconductor region, extending from the floating body region substantially to the main horizontal surface, and arranged between the first equipotential semiconductor region and the edge.

20. The semiconductor device of claim 19, wherein the semiconductor body further comprises at least one of:

a charge-generating structure arranged next to the main horizontal surface and in Ohmic contact with at least one of the first equipotential semiconductor region and the second equipotential semiconductor region;

a first charge-compensation structure arranged between the main horizontal surface and the embedded field-stop zone, and comprising, in a vertical cross-section substantially orthogonal to the main horizontal surface, a plurality of alternating first pillar regions of the first conductivity type and first pillar regions of the second conductivity type, the first pillar regions of the first conductivity type being in Ohmic contact with the embedded field-stop zone, and the first pillar regions of the second conductivity type being in Ohmic contact with the first metallization;

a first charge-compensation structure arranged between the main horizontal surface and the embedded field-stop zone, and comprising, in a vertical cross-section substantially orthogonal to the main horizontal surface, a plurality of alternating first pillar regions of the first conductivity type and insulated trench field-electrodes, the first pillar regions of the first conductivity type being in Ohmic contact with the embedded field-stop zone, wherein each of the trench field-electrodes comprises a field-electrode in Ohmic contact with the first metallization and a field-dielectric region separating the field-electrode from adjacent first n-type pillar regions;

a second charge-compensation structure arranged between the floating body region and the second metallization, and comprising, in a vertical cross-section substantially orthogonal to the main horizontal surface, a plurality of alternating second pillar regions of the first conductivity type and second pillar regions of the second conductivity type, the second pillar regions of the first conductivity type being in Ohmic contact with the embedded field-stop zone, and the second pillar regions of the second conductivity type being in Ohmic contact with floating body region;

a first semiconductor layer of the first conductivity type extending to the edge, adjoining the first semiconductor region, having a maximum doping concentration higher than the first maximum doping concentration, and arranged between the second charge-compensation structure and the second metallization;

a third equipotential semiconductor region of the first conductivity type embedded in the first semiconductor region and extending from the first semiconductor layer substantially to the main horizontal surface; and

a drain layer of the first conductivity type extending to the edge, adjoining first semiconductor layer, having a maximum doping concentration higher than the first semiconductor layer, and forming an Ohmic contact with the second metallization.