ELECTRODE CONTACT STRUCTURE FOR SEMICONDUCTOR DEVICE

• US 20150069610A1
• Filed: 11/13/2014
• Published: 03/12/2015
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Grivna, Gordon M.
• Granted Patent: US 10,355,125 B2
• Time in Patent Office: Days
• US Class Current: 257/741
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• CPC Class Codes: H01L 29/4236 within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/42364 characterised by the insulating layer, e.g. thickness or uniformity H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/4916 the conductor material next to the insulator being a silicon layer, e.g. polysilicon doped with boron, phosphorus or nitrogen H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/4933 with a silicide layer contacting the silicon layer, e.g. Polycide gate with a barrier layer between the silicide and silicon layers H01L29/4941
• CPC Class Codes: H01L 29/66348 with a recessed gate
• CPC Class Codes: H01L 29/66363 Thyristors
• CPC Class Codes: H01L 29/66719 With a step of forming an insulating sidewall spacer
• 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

In one embodiment, a method for forming a semiconductor device having a shield electrode includes forming first and second shield electrode contact portions within a contact trench. The first shield electrode contact portion can be formed recessed within the contact trench and includes a flat portion. The second shield electrode contact portion can be formed within the contact trench and makes contact to the first shield electrode contact portion along the flat portion.

Claims

1-16. -16. (canceled)

17. An electrode contact structure comprising:

a region of semiconductor material having first and second opposing major surfaces, wherein the region of semiconductor material includes an active area and a contact area;

a contact trench extending from the first major surface into the region of semiconductor material;

a first dielectric layer along surfaces of the contact trench;

a first shield electrode contact portion adjacent the first dielectric layer, wherein the first electrode contact portion is recessed below the first major surface and includes a flat portion parallel to the second major surface;

a second dielectric layer overlying a part of the first electrode contact portion; and

a second shield electrode contact portion in the contact trench and contacting the first electrode contact portion along the flat portion.

18. The structure of claim 17, wherein the first shield contact portion further forms at least one shield electrode within the active area.

19. The structure of claim 17 further comprising a conductive region formed in an upper portion of the second electrode contact portion.

20. The structure of claim 17, wherein the second dielectric layer comprises a thermal oxide.

21. An electrode contact structure comprising:

a region of semiconductor material having a major surface;

a contact trench extending from the major surface into the region of semiconductor material;

a first dielectric region along lower surfaces of the contact trench;

a first electrode contact portion adjacent the first dielectric region, wherein the first electrode contact portion is recessed below the major surface;

a second dielectric region along a part of an upper surface of the first electrode contact portion;

a third dielectric region along upper surfaces of the contact trench; and

a second electrode contact portion within the contact trench adjacent the third dielectric region and contacting the first electrode contact portion within the contact trench.

22. The structure of claim 21, wherein:

the first dielectric region is along the lower surfaces of the contact trench but not along the upper surfaces of the contact trench; and

the third dielectric region is along the upper surfaces of the contact trench but along the lower surfaces of the contract trench.

23. The structure of claim 21 further comprising spacers between the third dielectric region and the second electrode contact portion.

24. The structure of claim 21, wherein the second dielectric region extends out of the contact trench and overlaps the major surface of the region of semiconductor material.

25. The structure of claim 21, wherein the second electrode contact portion contacts the first electrode contact portion along a surface that is substantially orthogonal to sidewall surfaces of the contact trench.

26. The structure of claim 21 further comprising a conductive region in an upper portion of the second electrode contact portion.

27. The structure of claim 26, wherein the conductive region comprises a silicide region.

28. The structure of claim 21 further comprising:

an inter-layer dielectric overlying the major surface having an opening substantially aligned to the second electrode contact portion; and

a conductive plug in the opening and electrically coupled to the second electrode contact portion.

29. An electrode contact structure comprising:

a contact trench in a region of semiconductor material having first and second opposing major surfaces;

a first conductive contact portion in a lower portion of the contact trench and having a recessed surface substantially parallel to the second major surface, wherein the first conductive contact portion is insulated from the region of semiconductor material, and wherein the first conductive contact portion is further coupled to at least one electrode structure in an active portion of the region of semiconductor material; and

a second conductive contact portion in the contact trench and contacting the first conductive contact portion along the recessed surface.

30. The structure of claim 29 further comprising:

a first dielectric region between the first conductive contact portion and the region of semiconductor material; and

a second dielectric region between the second conductive portion and the region of semiconductor material.

31. The structure of claim 30 further comprising a third dielectric region between the first dielectric region and the second dielectric region.

32. The structure of claim 30 further comprising spacers between the second conductive portion and the second dielectric region.

33. The structure of claim 30, wherein the second dielectric layer overlaps the first major surface.

34. The structure of claim 30, wherein the first dielectric region comprises a deposited oxide.

35. The structure of claim 29 further comprising:

an inter-layer dielectric overlying the first major surface having an opening substantially aligned to the second conductive contact portion; and

a conductive plug in the opening and electrically coupled to the second conductive contact portion.

36. The structure of claim 29, wherein the electrode contact structure comprises a shield electrode contact structure.