Electronic device including a trench and a conductive structure therein

• US 8,969,956 B2
• Filed: 02/10/2014
• Issued: 03/03/2015
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Venkatraman, Prasad, Padmanabhan, Balaji
• Primary Examiner(s): Patel, Reema
• Application Number:
  US14/176,185
• Publication Number:
  US 20140151787A1
• Time in Patent Office: 386 Days
• Field of Search: 257/330, 257/331, 257/332, 438/259, 438/587, 438/588, 438/589
• US Class Current: 257/332
• 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 29/66727 with a step of recessing the source electrode
• 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 29/7811 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 29/7827 Vertical transistors H01L29/7802, H01L29/78642 take precedence

Abstract

An electronic device can include a transistor structure, including a patterned semiconductor layer overlying a substrate and having a primary surface, wherein the patterned semiconductor layer defines a first trench and a second trench that extend from the primary surface towards the substrate. The electronic device can further include a first conductive electrode and a gate electrode within the first trench. The electronic device can still further include a second conductive electrode within the second trench. The electronic device can include a source region within the patterned semiconductor layer and disposed between the first and second trenches. The electronic device can further include a body contact region within the patterned semiconductor layer and between the first and second trenches, wherein the body contact region is spaced apart from the primary surface. Processes of forming the electronic device can take advantage of forming all trenches during processing sequence.

Claims

1. An electronic device comprising a transistor structure, comprising:

a patterned semiconductor layer overlying a substrate and having a primary surface, wherein the patterned semiconductor layer defines a first trench, a second trench, and a third trench that extend from the primary surface towards the substrate, wherein the third trench is disposed between the first and second trenches, and wherein the first, second, and third trenches are disposed within an active region;

a first conductive structure within the first trench;

a first gate electrode within the first trench and electrically insulated from the first conductive structure;

a second conductive structure within the second trench;

a second gate electroge within the second trench and electrically insulated from the second conductive structure;

a third conductive structure within the third trench, wherein no gate electrode is disposed above the third conductive structure;

a source region within the patterned semiconductor layer and disposed between the first and second trenches; and

a body contact region within the patterned semiconductor layer and between the first and second trenches, wherein the body contact region is spaced apart from the primary surface.

2. The electronic device of claim 1, wherein, from a cross sectional view, the source region is disposed along opposite sides of the first trench.

3. The electronic device of claim 1, wherein the body contact region is spaced apart from a sidewall of the second trench.

4. The electronic device of claim 1, further comprising a conductive plug and an interconnect member, wherein the conductive plug extends between and directly contacts the interconnect member and the body contact region.

5. The electronic device of claim 1, wherein the first and second trenches have substantially a same depth.

6. The electronic device of claim 1, wherein the first trench is wider than the second trench.

7. The electronic device of claim 1, wherein the first and second conductive structures are electrically connected to each other.

8. An electronic device comprising a transistor structure, comprising:

a patterned semiconductor layer overlying a substrate and having a primary surface, wherein the patterned semiconductor layer defines a first trench and a second trench that extend from the primary surface towards the substrate and are within an active region;

a first conductive structure within the first trench;

a second conductive structure within the second trench;

a first insulating layer within the first trench between the first conductive structure and the semiconductor layer;

a second insulating layer within the second trench between the second conductive structure and the semiconductor layer;

a gate electrode within the first trench;

a third insulating layer within the first trench between the gate electrode and the first conductive structure; and

a body contact region within the patterned semiconductor layer and between the first and second trenches,

wherein the body contact region is spaced apart from the primary surface, and wherein no gate electrode is disposed above the second conductive structure.

9. The electronic device of claim 8, wherein the first and second trenches have substantially a same depth.

10. The electronic device of claim 8, wherein the first trench is wider than the second trench.

11. The electronic device of claim 8, wherein the patterned semiconductor layer defines additional first trenches and additional second trenches in the active region, wherein a ratio of a number of the first trenches to a number of the second trenches is approximately 1:

1.

12. The electronic device of claim 11, wherein the additional first trenches each have an additional first conductive structure and an additional gate electrode, and wherein the additional second trenches each have an additional second conductive structure and no gate electrode.

13. An electronic device comprising a transistor structure, comprising:

a patterned semiconductor layer overlying a substrate and having a primary surface, wherein the patterned semiconductor layer defines a first trench, a second trench, and a third trench that extend from the primary surface towards the substrate, wherein the first, second, and third trenches are within an active region, and the third trench is disposed between the first and second trenches;

a first conductive structure within the first trench;

a first gate electrode within the first trench and electrically insulated from the first conductive structure;

a second conductive structure within the second trench;

a second gate electrode within the second trench and electrically insulated from the second conductive structure; and

a third conductive structure within the third trench, wherein no gate electrode is disposed above the third conductive structure.

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

a first insulating layer disposed within the first trench and electrically insulating the first gate electrode from the first conductive structure; and

a second insulating layer disposed within the second trench and electrically insulating the second gate electrode from the second conductive structure.

15. The electronic device of claim 13, further comprising a body contact region disposed within the patterned semiconductor layer along opposite sides of the third trench, wherein the body contact region is spaced apart from the primary surface.

16. The electronic device of claim 13, further comprising a source region disposed within the patterned semiconductor layer along opposite sides of the third trench.

17. The electronic device of claim 13, wherein a ratio of a number of the first trenches to a number of the second trenches is approximately 1:

1.

18. The electronic device of claim 13, wherein the first, second and third trenches have substantially a same depth.

19. The electronic device of claim 13, wherein the first and second trenches are each wider than the third trench.

20. The electronic device of claim 13, wherein the first, second, and third conductive structures are electrically connected to each other.