METHOD OF PRODUCING A HIGH-VOLTAGE-RESISTANT SEMICONDUCTOR COMPONENT HAVING VERTICALLY CONDUCTIVE SEMICONDUCTOR BODY AREAS AND A TRENCH STRUCTURE

• US 20140203349A1
• Filed: 12/23/2013
• Published: 07/24/2014
• Est. Priority Date: 09/24/2004
• Status: Abandoned Application

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Pfirsch, Frank
• Application Number:
  US14/138,167
• Publication Number:
  US 20140203349A1
• Time in Patent Office: Days
• US Class Current: 257/328
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• CPC Class Codes: H01L 29/0878 Impurity concentration or distribution
• CPC Class Codes: H01L 29/41 characterised by their shape, relative sizes or dispositions
• 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 29/66712 Vertical DMOS transistors, i.e. VDMOS transistors
• CPC Class Codes: H01L 29/7802 Vertical DMOS transistors, i.e. VDMOS transistors
• CPC Class Codes: H01L 29/7815 with voltage or current sensing structure, e.g. emulator section, overcurrent sensing cell

Abstract

A high-voltage-resistant semiconductor component (1) has vertically conductive semiconductor areas (17) and a trench structure (5). These vertically conductive semiconductor areas are formed from semiconductor body areas (10) of a first conductivity type and are surrounded by a trench structure (5) on the upper face (6) of the semiconductor component. For this purpose the trench structure has a base (7) and a wall area (8) and is filled with a material (9) with a relatively high dielectric constant (ε_r). The base area (7) of the trench structure (5) is provided with a heavily doped semiconductor material (11) of the same conductivity type as the lightly doped semiconductor body areas (17), and/or having a metallically conductive material

Claims

1-25. -25. (canceled)

26. A high-voltage-resistant semiconductor component comprising:

a vertical MOS channel area, comprising;

lightly doped drift path regions of a first conductivity type, and a trench structure comprising a base area and a wall area, wherein a conductive buried layer is arranged in the base area of the trench structure, a material with a high relative dielectric constant is arranged on the conductive buried layer and a gate electrode is arranged on the material with a high relative dielectric constant.

27. The high-voltage-resistant semiconductor component according to claim 26, further comprising an upper electrode arranged between the gate electrode and the material with a high relative dielectric constant.

28. The high-voltage-resistant semiconductor component according to claim 27, further comprising a gate oxide arranged between the upper electrode and the gate electrode.

29. The high-voltage-resistant semiconductor component according to claim 27, wherein the upper electrode is coupled to a source.

30. The high-voltage-resistant semiconductor component according to claim 26, wherein the wall area of the trench structure further comprises an isolation layer.

31. The high-voltage-resistant semiconductor component according to claim 30, wherein the isolation layer comprises one or more of an oxide, a nitride, SiO₂, Si₃N₄, TiO₂, HfO₂, Ta₂O₅, Al₂O₃ and AlN.

32. The high-voltage-resistant semiconductor component according to claim 26, wherein the conductive buried layer comprises a heavily doped semiconductor material of the same conductivity type as the lightly doped drift path regions.

33. The high-voltage-resistant semiconductor component according to claim 32, wherein the heavily doped semiconductor material, has a material whose impurity concentration is:

N≧

ε

_r ε

₀(E_crit)²/E_g

where ε

_r is the relative dielectric constant, ε

₀ is the absolute dielectric constant of the vacuum, E_crit is the critical field strength, E_g is the band gap.

34. The high-voltage-resistant semiconductor component according to claim 32, wherein the heavily doped semiconductor material comprises a crystalline silicon, polysilicon or silicon carbide with an impurity concentration of:

N_D Or N_A≦

1·

10¹⁸ cm<sup>−

3</sup>

35. The high-voltage-resistant semiconductor component according to claim 26, wherein the conductive buried layer comprises a metallically conductive material.

36. The high-voltage-resistant semiconductor component according to claim 35, wherein the metallically conductive material comprises one of the group consisting of a silicide, a tungsten silicide, a cobalt silicide and a material comprising titanium, hafnium, tantalum or alloys thereof.

37. The high-voltage-resistant semiconductor component according to claim 26, further comprising source electrodes arranged alternately with the gate electrodes.

38. The high-voltage-resistant semiconductor component according to claim 37, wherein the source electrodes contact heavily doped regions of the first conductivity type.

39. The high-voltage-resistant semiconductor component according to claim 38, further comprising a heavily doped zone of a second conductivity type in direct contact with the source electrode.

40. The high-voltage-resistant semiconductor component according to claim 39, further comprising a medium-doped channel zone of the second conductivity type.

41. The high-voltage-resistant semiconductor component according to claim 26, wherein the trench structure is embedded in a lightly doped semiconductor body area of one conductivity type, which is arranged on a heavily doped substrate of the same conductivity type, with the filled trench structure surrounding a plurality of semiconductor body areas of the lightly doped semiconductor body area and the upper face areas of the semiconductor body areas having an MOS structure with individual source electrodes and individual gate electrodes, with a medium to heavily doped impurity zone of the opposite conductivity type being arranged in the upper face area of the semiconductor body areas, which impurity zone contains a gate channel area, with the impurity zone having an individual source electrode and with the plurality of individual source electrodes in the semiconductor body areas being electrically connected in parallel to form a common source electrode, and being electrically connected to the trench structure, while the gate channel area is covered by a gate oxide and has an individual gate electrode, with the plurality of individual gate electrodes in the semiconductor body areas being interconnected to form a common gate electrode, and with the heavily doped substrate of the same conductivity type as the lightly doped semiconductor body area having a metal coating as a large-area drain electrode on its lower face.

42. A method for production of a plurality of semiconductor chips from a semiconductor wafer which has semiconductor chip positions arranged in rows and columns, the method comprising:

producing a semiconductor wafer which is lightly doped with a first conductivity type or of an epitaxial layer which is lightly doped with the first conductivity type and is deposited on a semiconductor wafer which is heavily doped with the first or second conductivity type;

introducing trench structures with a base area and a wall area into a lightly doped semiconductor body area of the semiconductor chip positions on the semiconductor wafer;

introducing heavy doping of the same conductivity type as the lightly doped

semiconductor body area into the base area of the trench structures, or introducing a metallically conductive coating into the base area of the trench structures; and

introducing a material with a high relative dielectric constant into the trench structures.

43. The method as claimed in claim 42, wherein the heavy doping of the same conductivity type as the lightly doped semiconductor body areas is introduced into the base area of the trench structures by means of ion implantation technology.

44. The method as claimed in claim 42, wherein the metallically conductive coating is introduced to the base area of the trench structures by means of physical sputtering, vapor-deposition, or chemically by means of chemical gas-phase deposition or electrolytic deposition.

45. The method as claimed in claim 42, wherein before the introduction of the metallically conductive coating to the base area of the trench structures, the wall area of the trench structure and those surfaces of the semiconductor wafer which are not to be coated are selectively provided with a protective layer.