Semiconductor component and method for producing a semiconductor component

• US 9,142,444 B2
• Filed: 05/15/2013
• Issued: 09/22/2015
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Zundel, Markus, Bacher, Erwin, Behrendt, Andreas, Ortner, Joerg, Rieger, Walter, Zelsacher, Rudolf
• Primary Examiner(s): YUSHINA, GALINA G
• Application Number:
  US13/895,132
• Publication Number:
  US 20130323905A1
• Time in Patent Office: 860 Days
• Field of Search: 438/141, 438/143, 438/197, 438/212, 438/237, 438/249, 438/270, 438/689, 438/692, 438/700
• US Class Current: 1/1
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264
• CPC Class Codes: H01L 29/0657 characterised by the shape of the body
• 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 29/7803 structurally associated with at least one other device assemblies H01L25/00; integrated circuits H01L27/00
• CPC Class Codes: H01L 29/7804 the other device being a pn-junction diode
• 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
• CPC Class Codes: H01L 29/861 Diodes

Abstract

A semiconductor component comprises a semiconductor body with at least one protective trench in the semiconductor body. An insulation layer is situated at least at the bottom of the protective trench. An electrically conductive layer having a thickness D is formed on the insulation layer in the protective trench, wherein the electrically conductive layer only partly fills the protective trench.

Claims

1. A method for producing a semiconductor component, comprising:

providing a semiconductor body, producing at least one protective trench in the semiconductor body,

producing an insulation layer on the sidewalls and at the bottom of the protective trench,

producing an electrically conductive layer having a thickness D on the insulation layer in the protective trench, wherein the electrically conductive layer only partly fills the protective trench,

applying another insulation layer over the electrically conductive layer, the another insulation layer disposed at least partially in the protective trench and having a connection opening providing access to the electrically conductive layer,

applying a protective layer in the protective trench such that the protective layer is at least partially on the electrically conductive layer.

2. The method according to claim 1, wherein, in one production step, the protective trench is produced together with a cell trench in the semiconductor body.

3. The method according to claim 1, wherein the electrically conductive layer is produced in such a way that at least one partial region of the layer surface runs parallel to a main surface of the semiconductor body.

4. The method according to claim 1, wherein the electrically conductive layer is provided with a dopant at least locally.

5. The method according to claim 4, wherein the dopant is implanted into the electrically conductive layer and subsequently activated.

6. The method according to claim 1, wherein a portion of the electrically conductive layer is firstly partly produced on a main surface of the semiconductor body and is subsequently removed.

7. The method according to claim 6, wherein the removal of the electrically conductive layer on the main surface of the semiconductor body is by way of chemical mechanical polishing.

8. The method according to claim 1, wherein the electrically conductive layer is arranged at the bottom of the protective trench only.

9. The method according to claim 1, further comprising forming an electrical component in the electrically conductive layer.

10. The method according to claim 9, wherein the at least one part of the electrical component is formed in a part of the electrically conductive layer that is arranged at the bottom of the protective trench.

11. The method according to claim 1, wherein the electrically conductive layer only partially covers a horizontal surface of the insulation layer at least at the bottom of the protective trench.

12. The method according to claim 11, wherein the another insulation layer at least covering vertical edge surfaces of the electrically conductive layer.

13. The method according to claim 1, wherein the electrically conductive layer has a substantially planar bottom surface adjacent to a substantially planar surface of the insulation layer.

14. The method according to claim 1, wherein the at least one protective trench in the semiconductor body has a width B1, the width B1 being at least greater than 2.5 times the thickness D (B1>

2.5×

D).