Semiconductor component and methods for producing a semiconductor component

• US 9,275,895 B2
• Filed: 01/28/2014
• Issued: 03/01/2016
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Meiser, Andreas, Hartner, Walter, Gruber, Hermann, Bonart, Dietrich, Gross, Thomas
• Primary Examiner(s): Menz, Laura
• Assistant Examiner(s): Malek, Maliheh
• Application Number:
  US14/166,090
• Publication Number:
  US 20140141608A1
• Time in Patent Office: 763 Days
• Field of Search: 438242-248, 438/259, 438/270, 438386-391, 257301-302, 257304-305, 257/311, 257/330, 257332-334, 257/520, 257E27091-E27092, 257/E29.346, 257/E21.396, 257/E21.585, 257/E21.564, 257/E21.655, 257/E29.121, 257/E29.26, 257/E23.131
• US Class Current: 1/1
• CPC Class Codes: H01L 21/76286 Lateral isolation by refilling of trenches with polycristalline material
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688

Abstract

A method for producing a semiconductor component with a semiconductor body includes providing a substrate of a first conductivity type. A buried semiconductor layer of a second conductivity type is provided on the substrate. A functional unit semiconductor layer is provided on the buried semiconductor layer. At least one trench, which reaches into the substrate, is formed in the semiconductor body. An insulating layer is formed, which covers inner walls of the trench and electrically insulates the trench interior from the functional unit semiconductor layer and the buried semiconductor layer, the insulating layer having at least one opening in the region of the trench bottom. The at least one trench is filled with an electrically conductive semiconductor material of the first conductivity type, wherein the electrically conductive semiconductor material forms an electrical contact from a surface of the semiconductor body to the substrate.

Claims

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

providing a substrate of a first conductivity type;

providing a buried semiconductor layer of a second conductivity type on the substrate;

providing a functional unit semiconductor layer on the buried semiconductor layer;

forming, by a single patterned mask process, at least one trench in the semiconductor body which reaches into the substrate;

forming an insulating layer, which covers inner walls of the trench and electrically insulates the trench interior from the functional unit semiconductor layer and the buried semiconductor layer, the insulating layer having at least one opening in the region of the trench bottom, wherein forming the insulating layer comprises forming a thermal oxide covering inner walls of the trench and forming an oxide by conformal deposition partially in direct contact with the thermal oxide and removing part of the oxide by a spacer etch process; and

filling the at least one trench with an electrically conductive semiconductor material of the first conductivity type, wherein the electrically conductive semiconductor material forms an electrical contact from a surface of the semiconductor body to the substrate and is in direct contact with the oxide formed by conformal deposition.

2. The method of claim 1, further comprising, prior to filling the at least one trench with the electrically conductive semiconductor material, introducing dopants of the first conductivity type into the at least one trench, so that the doping concentration of that region of the substrate which adjoins the trench bottom of the at least one trench is increased with respect to the doping concentration of the substrate.

3. The method as claimed in claim 1, further comprising prior to filling the trench with the electrically conductive material, forming a silicide at least on the bottom of the trench, and filling the trench with a semiconductor material of the first conduction type.

4. The method as claimed in claim 1, further comprising forming the silicide is formed by the deposition of a metal at least on the bottom of the trench.

5. The method of claim 4, wherein the metal is selected from a group comprising Ti, W, Co, Ta, Hf and other transition metals.