Method and device including transistor component having a field electrode

• US 8,072,028 B2
• Filed: 10/26/2009
• Issued: 12/06/2011
• Est. Priority Date: 10/26/2009
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Krumrey, Joachim, Noebauer, Gerhard, Poelzl, Martin, Probst, Marc
• Primary Examiner(s): Pham, Long
• Application Number:
  US12/605,933
• Publication Number:
  US 20110095360A1
• Time in Patent Office: 771 Days
• Field of Search: 257/334, 257/288, 257/622
• US Class Current: 257/334
• CPC Class Codes: H01L 29/0696 of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• 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 29/66727 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 29/7803 structurally associated with at least one other device assemblies H01L25/00; integrated circuits H01L27/00
• 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 transistor component and method of forming a transistor component. One embodiment provides a semiconductor arrangement including a semiconductor body having a at least one first trench, a first field electrode arranged in the lower trench section of the at least one first trench and being insulated from the semiconductor body by a field electrode dielectric. A dielectric layer is formed on the first field electrode in the at least one first trench, including depositing a dielectric material on a first side of the semiconductor body and on the field plate at a higher deposition rate than on sidewalls of the at least one first trench.

Claims

1. A transistor component, including:

a semiconductor body having a first side and at least one first trench extending from the first side, the at least one first trench having sidewalls and lower and upper trench sections;

a first field electrode arranged in the lower trench section of the at least one first trench and being insulated from the semiconductor body by a field electrode dielectric, the first field electrode having a vertical length;

a dielectric layer on the first field electrode in the at least one first trench;

a gate dielectric, the gate dielectric at least lining the sidewalls in the upper trench section of the at least one first trench;

a gate electrode in the upper trench section, gate electrode being insulated from the first field electrode by the dielectric layer, a thickness of the dielectric layer being at least 50% of the vertical length of the field electrode;

an edge region of the semiconductor body;

a second trench arranged in the edge region, and extending from the first side into the semiconductor body;

a second field electrode arranged in the second trench, the second field electrode being insulated from the semiconductor body by a second field electrode dielectric, and extending further in the direction of the first side than the first field electrode.

2. The transistor component of claim 1, wherein the thickness of the dielectric layer is less than or equal to the vertical length of the first field electrode.

3. The transistor component of claim 1,

wherein the thickness of the dielectric layer is a thickness in the middle of the trench and is measured in a vertical direction of the semiconductor body, and

wherein the vertical length of the first field electrode is a length in the middle of the trench and is measured in a vertical direction of the semiconductor body.

4. The transistor component of claim 2, wherein the second field electrode extends to the first side or beyond the first side.

5. The transistor component of claim 1, further including a MOS gated diode structure, the MOS gated diode structure including:

a third trench in the semiconductor having a lower trench section and an upper trench section;

a third field electrode arranged in the third trench and insulated from the semiconductor body by a third field electrode dielectric in the lower trench section;

a second gate electrode arranged between the third field electrode and the semiconductor body in the upper trench section, and insulated from the semiconductor body and the third field electrode by a dielectric layer.