Integrated circuit including a trench transistor having two control electrodes

• US 8,093,655 B2
• Filed: 06/08/2007
• Issued: 01/10/2012
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Hirler, Franz, Roesch, Maximilian, Siemieniec, Ralf
• Primary Examiner(s): Matthews, Colleen
• Assistant Examiner(s): YUSHINA, GALINA G
• Application Number:
  US11/760,275
• Publication Number:
  US 20070296029A1
• Time in Patent Office: 1,677 Days
• Field of Search: 257/302, 257/329, 257/330, 257/331, 257/334, 257/307, 257/500, 257/328, 257/374, 257/77, 257/E29.2, 257/E29.201, 257/E29.257, 257/E29.262, 257/E29.264, 257/E29.267, 257/202, 257/250, 257/249, 257/332, 257/E29.028, 257/341, 257/E29.067, 438/259, 438/270, 365/149
• US Class Current: 257/341
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• CPC Class Codes: H01L 29/41741 for vertical or pseudo-vertical devices
• 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 29/4238 characterised by the surface lay-out
• 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

An integrated circuit including a field effect controllable trench transistor having two-control electrodes is disclosed. One embodiment provides a trench having a first control electrode and a second control electrode. A first electrical line is provided in an edge structure for electrically contact-connecting second control electrode.

Claims

1. An integrated circuit having a trench transistor and comprising:

a semiconductor body, subdivided into a cell array region having at least one cell array and an edge structure framing the cell array, the semiconductor body being provided with at least one doped source connection zone and at least one doped drain connection zone in the cell array;

wherein the source connection zone is supplied by source potential through a first connection electrode and the drain connection zone is supplied by drain potential through a second connection electrode;

a plurality of active trenches formed in the semiconductor body;

a plurality of first control electrodes formed in the active trenches, wherein each first control electrode of the plurality of first control electrodes is formed in the active trench designated for this first control electrode, and each of the plurality of first control electrodes being insulated from the semiconductor body by a first insulation layer in the trench designated for this first control electrode;

a plurality of second control electrodes, each second control electrode of the plurality of second control electrodes is arranged adjacent to and separated from a corresponding first control electrode located in the active trench designated for the first control electrode, the plurality of second control electrodes being field electrodes and each of the plurality of second control electrodes is insulated by a second insulation layer from the semiconductor body and the first control electrode located in the same active trench, the active trenches and the plurality of first control electrodes and the plurality of second control electrodes formed therein extending in a first lateral direction,

wherein the plurality of first control electrodes are a plurality of gate electrodes and electrically connected to a first electrical line being supplied by gate potential; and

wherein in the edge structure a selectable number of the plurality of second control electrodes are electrically connected to the first connection electrode through first connection means and a selectable number of the plurality of second control electrodes are electrically connected to a second electrical line connected to the plurality of first control electrodes through a second connection means,

such that in the edge structure a part of the plurality of second control electrodes is electrically connected through the first connection electrode to the source potential and a part of the plurality of second control electrodes is contacted through the plurality of first control electrodes to the gate potential.

2. The integrated circuit of claim 1, wherein the plurality of second control electrodes are contact-connected by the first connection electrode and by the first connection means in a second lateral direction perpendicular to the extension direction of active trenches with a selectable contact-connection scheme that is repeated substantially periodically in this direction.

3. The integrated circuit of claim 1, wherein the plurality of second control electrodes are contact-connected by in the edge structure by the connection means to the first electrical line and by the second connection means to the second electrical line in a second lateral direction perpendicular to the lateral extension direction of trenches with a selectable contact-connection scheme that is repeated substantially periodically in this direction.

4. The integrated circuit of claim 1, wherein the second electrical line is electrically conductively connected to the first connection electrode.

5. The integrated circuit of claim 1, wherein the first electrical line in the edge structure comprises a third connection means for electrically connecting the first electrical line and the plurality of first control electrodes.

6. The integrated circuit of claim 1, wherein the first connection means for electrically connecting one or more of the plurality of second control electrodes to the first electrical line comprise an electrical contact formed in a contact hole.

7. The integrated circuit of claim 1, wherein the second connection means for electrically connecting one or more of the plurality of second control electrodes to the second electrical line comprises an electrical contact formed in a contact hole.

8. The integrated circuit of claim 1, wherein the cell array region comprises a plurality of cell arrays which are separated from each other by the edge structure.

9. The integrated circuit of claim 1, wherein the active trenches and the plurality of first control electrodes and the plurality of second control electrodes extend into the edge structure.

10. The integrated circuit of claim 1, wherein the plurality of first control electrodes are electrically connected in the edge structure to the first electrical line formed therein.