Semiconductor component and method for producing it

• US 7,446,373 B2
• Filed: 09/10/2004
• Issued: 11/04/2008
• Est. Priority Date: 09/10/2003
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Hirler, Franz, Zundel, Markus, Kotz, Dietmar, Willmeroth, Armin, Peri, Hermann, Zelsacher, Rudolf
• Primary Examiner(s): Purvis; Sue A.
• Assistant Examiner(s): Erdem; Fazli
• Application Number:
  US10/939,154
• Publication Number:
  US 20050110077A1
• Time in Patent Office: 1,516 Days
• Field of Search: 257/329, 257/330, 257/331, 257/332, 257/137, 257/409, 257/410, 257/338, 257/327, 257/328, 257/333, 257/334, 257/E29.012, 257/E29.04, 257/E29.133, 438/409, 438/459
• US Class Current: 257/330
• 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 29/0847 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 29/42368 the thickness being non-uniform
• 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

Abstract

A semiconductor component and also a method for producing it are disclosed. In one embodiment, the semiconductor component includes a surface region or a modified doping region is provided alternatively or simultaneously in the edge region of the cell array, in which surface region or modified doping region the doping concentration is lowered and/or in which surface region or modified doping region the conductivity type is formed such that it is opposite to the conductivity type of the actual semiconductor material region, or in which a field plate region is provided.

Claims

1. A semiconductor component, in which, in a semiconductor material region or chip, provision is made of a trench structure semiconductor element arrangement with a semiconductor element cell array of a plurality of trench structure semiconductor elements arranged in strip form, in particular, in trench structures or trenches of the semiconductor material region, in which gate electrode regions or gate regions of the trench structure semiconductor elements are formed essentially in the interior of a respective trench structure and, in particular, in a manner electrically insulated from wall regions of the respective trench structure by an insulating oxide layer, in which source regions, body regions and, if appropriate, body contact regions of the trench structure semiconductor elements are in each case arranged in the mesa regions of the semiconductor material region between adjacent trench structures, the source regions in particular in each case being genuinely contained in the assigned body regions and in particular having a common surface region with the latter, in which the source regions and essentially the semiconductor material region are formed with a first conductivity type or conduction type and the body regions and, if appropriate, the body contact regions are formed with a second conductivity type or conduction type, and in which, at least in a first or upper edge region of the cell array and/or of the semiconductor material region and/or in a second or lateral edge region of the cell array and/or of the semiconductor material region, a surface region or modified doping region is provided which laterally encloses or embeds lateral end regions of the respective trench structure or at least one marginal mesa region with respect to the second or lateral edge region of a corresponding marginal trench structure and in which the doping or dopant concentration is formed such that it is lowered, in particular with respect to an actual doping concentration of a first epitaxial zone, and/or in which the conductivity type or conduction type is formed such that it is opposite to the actual conductivity type or conduction type of the semiconductor material region and, in particular, is of low concentration.

2. The semiconductor component according to claim 1, comprising providing a field plate region at least in the first or upper edge region of the cell array and/or of the semiconductor material region and/or in the second or lateral edge region of the cell array and/or of the semiconductor material region.

3. A semiconductor component, in which, in a semiconductor material region or chip, provision is made of a trench structure semiconductor element arrangement with a semiconductor element cell array of a plurality of trench structure semiconductor elements arranged in strip form, in particular, in trench structures or trenches of the semiconductor material region, in which gate electrode regions or gate regions of the trench structure semiconductor elements are formed essentially in the interior of a respective trench structure and, in particular, in a manner electrically insulated from wall regions of the respective trench structure by an insulating oxide layer, in which source regions, body regions and, if appropriate, body contact regions of the trench structure semiconductor elements are in each case arranged in the mesa regions of the semiconductor material region between adjacent trench structures, the source regions in particular in each case being genuinely contained in the assigned body regions and in particular having a common surface region with the latter, in which the source regions and essentially the semiconductor material region are formed with a first conductivity type (n) or conduction type (n) and the body regions and, if appropriate, the body contact regions are formed with a second conductivity type (p) or conduction type (p), and in which a field plate region is provided at least in a first or upper edge region of the cell array and/or of the semiconductor material region and/or in a second or lateral edge region of the cell array and/or of the semiconductor material region.

4. The semiconductor component according to claim 3, comprising providing, at least in the first or upper edge region of the cell array and/or of the semiconductor material region and/or in the second or lateral edge region of the cell array and/or of the semiconductor material region, a surface region or modified doping region which laterally encloses or embeds lateral end regions of the respective trench structure or at least one marginal mesa region with respect to the second or lateral edge region of a corresponding marginal trench structure and in which the doping or dopant concentration is formed such that it is lowered, in particular with respect to an actual doping concentration of a first epitaxial zone, and/or in which the conductivity type or conduction type is formed such that it is opposite to the actual conductivity type (n) or conduction type (n) of the semiconductor material region and, in particular, is of low concentration.

5. The semiconductor component according to claim 4, comprising forming the modified doping region essentially in a manner patterned laterally or over the whole area.

6. The semiconductor component according to claim 4, comprising wherein, in the surface region or in the modified doping region, the concentration of the doping is formed by choosing the dopant concentrations at below approximately 90% or less of the customary dopant concentration of the first epitaxial zone, preferably below approximately 80% thereof, further preferably below approximately 50% thereof, in particular below approximately 10¹⁶ cm⁻

3 for a semiconductor component with a breakdown voltage in the region of approximately 60 V.

7. The semiconductor component according to claim 4, comprising extending the surface region or the modified doping region vertically as far as a depth which vertically encloses or embeds the source regions, the body regions and, if appropriate, the body contact regions.

8. The semiconductor component according to claim 4, comprising extending the surface region or the modified doping region vertically as far as a depth which almost reaches the depth of the trench structures, in particular approximately 90% thereof, but does not exceed it.

9. The semiconductor component according to claim 4, comprising forming the surface region or the modified doping region as an epitaxial zone or as a vertical sequence of a plurality of epitaxial zones.

10. The semiconductor component according to claim 3, comprising providing the field plate region in the respective trench structure in an upper section of the trench structure, in particular above undesired breakdown regions of the respective trench structure semiconductor element that are to be avoided.

11. The semiconductor component according to claim 3, comprising wherein the trench structure semiconductor element provided is a trench structure transistor device or a trench transistor, in particular a field plate transistor with a field plate in the respective trench structure, an n-channel trench transistor device, a p-channel trench transistor device and/or a trench transistor with a plurality of electrodes in the trench structure.

12. The semiconductor component according to claim 3, comprising providing a trench structure IGBT as the trench structure semiconductor element.

13. The semiconductor component according to claim 3, comprising forming the semiconductor element cell array such that it is patterned in open fashion.

14. The semiconductor component according to claim 3, comprising forming the semiconductor element cell array such that it is patterned in closed fashion, in particular with additional trench structures or transverse trenches that run transversely with respect to the trench structures.

15. The semiconductor component according to claim 13, comprising wherein the open patterning is realized by providing between the cell array and the first or upper edge region of the cell array and/or of the semiconductor material region or of the chip, at the vertical level of the trench structure, continuously semiconductor material and in particular in the form of a mesa, in particular a silicon material and/or in particular in a manner reaching from the surface of the cell array or of the semiconductor material region or chip as far as the depth of the trench structure.

16. The semiconductor component according to claim 3, comprising forming the cell array by a plurality of essentially identical trench structures that are spaced apart equidistantly in the form of an essentially homogeneous strip arrangement, and in that in particular an essentially homogeneous and strip-type mesa is thereby realized.

17. The semiconductor component according to claim 3, comprising wherein the width D_Mesa of the mesa region respectively situated between two adjacent trench structures is less than the width D_TRENCH of the trench structure, where in particular D_Mesa<

D_TRENCH holds true.

18. The semiconductor component according to claim 3, comprising wherein the width D_Mesa of the mesa region respectively situated between two adjacent trench structures is less than 2.5 times the thickness D_FOX of the field oxide in the respective trench structure.

19. A semiconductor component, comprising:

a semiconductor material region including a semiconductor element cell array of a plurality of trench structure semiconductor elements, the semiconductor element cell array defining an edge region, and

a modified doping region provided in the edge region, the modified doping region being of a first conductivity type that is opposite to a second conductivity type of the semiconductor material region, wherein the modified doping region extends vertically a depth that is approximately 90% of a depth of the trench structures.

20. The semiconductor component of claim 19, wherein the modified doping region has a low doping concentration with respect to an actual doping concentration of a separate epitaxial zone.

21. The semiconductor component of claim 19, wherein the modified doping region is patterned laterally over substantially an entire area of the edge region.

22. The semiconductor component of claim 19, wherein the modified doping region is formed as one of an epitaxial zone and a vertical sequence of a plurality of epitaxial zones.

23. The semiconductor component of claim 19, wherein each of the plurality of trench structure semiconductor elements is one of a field plate transistor with a field plate in the trench structure, an n-channel transistor device, a p-channel trench transistor device, and a trench transistor with a plurality of electrodes.

24. The semiconductor component of claim 19, wherein the semiconductor element cell array is patterned in an open fashion.