Semiconductor Device and Method of Manufacturing a Semiconductor Device

Patent metadata

Field	Value
Publication number	US-2016104797-A1
Application number	US-201514871845-A
Country	US
Kind code	A1
Filing date	Sep 30, 2015
Priority date	Oct 13, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

A semiconductor device comprises a gate electrode in a trench in a semiconductor body. The gate electrode comprises a plurality of gate segments disposed along an extension direction of the trench, the gate segments being connected to neighboring gate segments by means of connection elements. A distance between adjacent gate segments is equal to or smaller than 0.5*L, wherein L denotes a length of each of the gate segments, the length being measured along the extension direction of the trench.

First claim

1 . A semiconductor device comprising a gate electrode in a trench in a semiconductor body,
the gate electrode comprising a plurality of gate segments disposed along an extension direction of the trench, the gate segments being connected to neighboring gate segments by means of connection elements, wherein a distance between adjacent gate segments is equal to or smaller than 0.5*L, wherein L denotes a length of each of the gate segments, the length being measured along the extension direction of the trench.

2 . The semiconductor device according to claim 1 , further comprising a field plate disposed in the trench.

3 . The semiconductor device according to claim 2 , wherein the field plate comprises a plurality of field plate segments disposed along the extension direction of the trench, the field plate segments being electrically connected to neighboring field plate segments by means of second connection elements.

4 . The semiconductor device according to claim 3 , further comprising a field oxide disposed between the field plate segments and the semiconductor body, wherein a length C 2 of the second connection elements fulfills the following relationship 0.5*t≦C 2 ≦1.5 t, wherein t denotes a thickness of the field oxide.

5 . The semiconductor device according to claim 3 , wherein a depth of the field plate segments is at least the double of a depth of the second connection element.

6 . A semiconductor device comprising a gate electrode in a trench in a semiconductor body,
the gate electrode comprising a plurality of gate segments disposed along an extension direction of the trench, the gate segments being electrically connected to neighboring gate segments by means of connection elements,
the semiconductor device further comprising a source region disposed at a surface of the semiconductor body adjacent to the trench, the source region comprising a plurality of source segments separated from each other and disposed along the extension direction of the trench.

7 . The semiconductor device according to claim 6 , wherein the source segments are disposed adjacent to the gate segments.

8 . The semiconductor device according to claim 6 , further comprising a dielectric layer at a sidewall of the trench, the dielectric layer having a first thickness adjacent to gate segments and a second thickness adjacent to connection elements.

9 . The semiconductor device according to claim 6 , further comprising a field plate in the trench and a field oxide layer between the field plate and adjacent semiconductor body material, wherein the second thickness corresponds to a thickness of the field oxide layer.

10 . The semiconductor device according to claim 6 , wherein a length of the gate segments is approximately equal to or larger than a distance between adjacent gate segments, the length being measured along the extension direction of the trench.

11 . The semiconductor device according to claim 9 , wherein the field plate comprises a plurality of field plate segments disposed along the extension direction of the trench, the field plate segments being electrically connected to neighboring field plate segments by means of second connection elements.

12 . A semiconductor device comprising a gate electrode and a field plate, the gate electrode and the field plate being disposed in a trench formed in a semiconductor body,
the field plate comprising a plurality of field plate segments disposed along an extension direction of the trench, the field plate segments being electrically connected to neighboring field plate segments by means of second connection elements.

13 . The semiconductor device according to claim 12 further comprising a field dielectric layer between the field plate and the semiconductor body, wherein a distance between adjacent field plate segments corresponds to a thickness of the field dielectric layer, the distance being measured along the extension direction of the trench.

14 . The semiconductor device according to claim 12 , wherein the length of the field plate segments L 2 fulfills the following relationship: 0.5*c 2 ≦L 2 ≦1.5*c, wherein c 2 denotes the distance between adjacent field plate segments.

15 . The semiconductor device according to claim 12 , wherein the gate electrode comprises a plurality of gate segments disposed along the extension direction of the trench, the gate segments being electrically connected to neighboring gate segments by means of further connection elements.

16 . The semiconductor device according to claim 15 , wherein the gate segments have portions that do not overlap with the field plate segments.

Assignees

• Infineon Technologies Austria
• Infineon Technologies Ag

Inventors

• Poelzl Martin
• Ehrentraut Georg
• Hirler Franz
• Roesch Maximilian

Classifications

• H10D64/117

  Recessed field plates, e.g. trench field plates or buried field plates · CPC title

• H10D64/112

  comprising multiple field plate segments · CPC title

• H10D30/668

  having trench gate electrodes, e.g. UMOS transistors · CPC title

• H10D30/0297

  using recessing of the gate electrodes, e.g. to form trench gate electrodes · CPC title

• H10D62/127 Primary

  of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs · CPC title