Electronic device including a termination structure

• US 10,236,342 B2
• Filed: 04/07/2017
• Issued: 03/19/2019
• Est. Priority Date: 04/07/2017
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Loechelt, Gary H.
• Primary Examiner(s): Yushina, Galina G
• Application Number:
  US15/481,523
• Publication Number:
  US 20180294332A1
• Time in Patent Office: 711 Days
• CPC Class Codes: H01L 29/0615 by the doping profile or the shape or the arrangement of the PN junction, or with supplementary regions, e.g. junction termination extension [JTE] LDD or drain offset regions H01L29/7833
• 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 29/0657 characterised by the shape of the body
• CPC Class Codes: H01L 29/0847 of field-effect transistors with insulated gate H01L29/0653 takes precedence; with a passive supplementary region between source or drain and substrate related to punch-through, capacity or isolation phenomena H01L29/1079; with LDD or DDD structure H01L29/7833; for thin film transistors H01L29/78618
• CPC Class Codes: H01L 29/0878 Impurity concentration or distribution
• CPC Class Codes: H01L 29/0886 Shape
• 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 29/36 characterised by the concentration or distribution of impurities in the bulk material within semiconductor regions H01L29/06
• CPC Class Codes: H01L 29/4236 within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/66568 Lateral single gate silicon transistors
• CPC Class Codes: H01L 29/66681 Lateral DMOS transistors, i.e. LDMOS transistors
• CPC Class Codes: H01L 29/66734 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• 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 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/7823 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402
• CPC Class Codes: H01L 29/7825 with trench gate electrode trench gate electrodes per se H01L29/4236

Abstract

An electronic device can include a termination structure that includes a substrate, a semiconductor layer, and a first trench. The substrate includes a semiconductor material of a first conductivity type. The semiconductor layer has a second conductivity type opposite the first conductivity type and overlies the substrate and has a primary surface. The first trench extends through a majority of a thickness of the semiconductor layer. In an embodiment, a body extension region of the second conductivity type is adjacent to the primary surface and spaced apart from the first trench. In another embodiment, a doped region of the first conductivity type is adjacent to the primary surface and abuts the first trench. In a further embodiment, the termination structure can include a second trench extending through a majority of the thickness of the semiconductor layer and a doped region is spaced apart from the first and second trenches.

Claims

1. An electronic device including a termination structure, the termination structure comprising:

a substrate including a semiconductor material of a first conductivity type;

a first semiconductor layer of a second conductivity type opposite the first conductivity type, wherein the first semiconductor layer overlies the substrate and has a primary surface;

a first trench extending through a majority of a thickness of the first semiconductor layer;

a second trench extending through at least part of the first semiconductor layer and spaced apart from the first trench; and

a body extension region of the second conductivity type along the primary surface of the first semiconductor layer and spaced apart from and between the first and second trenches, wherein the body extension region has a higher dopant concentration than the first semiconductor layer; and

a first doped region of the first conductivity type along the primary surface of the first semiconductor layer and disposed between the first and second trenches.

2. The electronic device of claim 1, wherein the first doped region is disposed between the first trench and the body extension region.

3. The electronic device of claim 2, wherein the first doped region abuts the first trench.

4. The electronic device of claim 3, wherein the first doped region is disposed between and spaced apart from each of the body extension region and the second trench.

5. The electronic device of claim 4, wherein the first doped region electrically floats.

6. The electronic device of claim 1, further comprising a second doped region of the first conductivity type extending along a majority of the first trench.

7. The electronic device of claim 6, wherein the second doped region is spaced apart from the primary surface of the first semiconductor layer.

8. The electronic device of claim 7, further comprising a second semiconductor layer of the first conductivity type disposed between the substrate and the first semiconductor layer, wherein the second semiconductor layer has a lower dopant concentration as compared to each of the first doped region and the substrate.

9. The electronic device of claim 1, further comprising a first metal contact to the body extension region.

10. The electronic device of claim 9, further comprising:

a semiconductor material of a second conductivity type disposed between the first and second trenches and having a dopant concentration no greater than 10¹⁷ atoms/cm³; and

a second metal contact to the semiconductor material between the first and second trenches, wherein the semiconductor material does not include a body region where the second metal contact contacts the semiconductor material.

11. The electronic device of claim 1, further comprising:

a second semiconductor layer of the first conductivity type disposed between the substrate and the first semiconductor layer; and

a second doped region of the first conductivity type, wherein the second doped region is spaced apart from the primary surface of the first semiconductor layer, extends along most of the first trench, and is along a conduction path between the first doped region and the substrate,

wherein each of the first and second doped regions has a higher dopant concentration as compared to each of the first and second semiconductor layers.

12. The electronic device of claim 11, further comprising a third doped region of the first conductivity type, wherein:

the first doped region abuts the first trench;

the third doped region is spaced apart from the body extension region and the first and second trenches; and

the third doped region electrically floats and has a higher dopant concentration as compared to each of the first and second semiconductor layers.

13. An electronic device including a termination structure, the termination structure comprising:

a substrate including a semiconductor material of a first conductivity type;

a first semiconductor layer of a second conductivity type opposite the first conductivity type, wherein the first semiconductor layer overlies the substrate and has a primary surface;

a first trench extending through a majority of a thickness of the first semiconductor layer;

a first doped region of the first conductivity type adjacent to the primary surface of the first semiconductor layer and abutting the first trench; and

a body extension region of the second conductivity type adjacent to the primary surface of the first semiconductor layer, and the first doped region is disposed between the body extension region and the first trench.

14. The electronic device of claim 13, further comprising:

a second trench extending through at least part of the first semiconductor layer and spaced apart from first trench and the first doped region; and

a second doped region of the first conductivity type adjacent to the primary surface of the first semiconductor layer and abutting the second trench.

15. The electronic device of claim 13, further comprising:

a second semiconductor layer of the first conductivity type disposed between the substrate and the first semiconductor layer; and

a second doped region of the first conductivity type extending along a majority of the first trench, wherein the second doped region has a higher dopant concentration as compared to each of the first and second semiconductor layers.

16. The electronic device of claim 15, wherein the second doped region is along a conduction path between the first doped region and the substrate.

17. The electronic device of claim 15, further comprising an active region, wherein the electronic device is configured such that a drain-to-source avalanche breakdown is lower within the active region as compared to within the termination structure.

18. The electronic device of claim 15, further comprising a second doped region of the first conductivity type, wherein the second doped region is adjacent to the primary surface of the first semiconductor layer, and the body extension region is disposed between the first and second doped regions.

19. An electronic device including a termination structure, the termination structure comprising:

a substrate including a semiconductor material of a first conductivity type;

a first semiconductor layer of second conductivity type opposite the first conductivity type, wherein the first semiconductor layer overlies the substrate and has a primary surface;

a first trench extending through a majority of a thickness of the first semiconductor layer;

a first doped region underlying the first trench and extending to the substrate;

a second trench extending through a majority of the thickness of the first semiconductor layer and spaced apart from the first trench;

a second doped region underlying the second trench, extending to the substrate, and spaced apart from the first doped region; and

a third doped region of the first conductivity type, wherein the third doped region is adjacent to the primary surface of the first semiconductor layer and spaced apart from the first and second trenches.

20. The electronic device of claim 19, wherein the first doped region electrically floats.