Semiconductor component and methods for producing a semiconductor component

• US 8,637,378 B2
• Filed: 06/09/2011
• Issued: 01/28/2014
• 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 M
• Assistant Examiner(s): Malek, Maliheh
• Application Number:
  US13/156,970
• Publication Number:
  US 20110256688A1
• Time in Patent Office: 964 Days
• Field of Search: 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, 438242-248, 438/259, 438/270, 438386-391
• US Class Current: 438/391
• 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 semiconductor component includes a semiconductor body, in which are formed: a substrate of a first conduction type, a buried semiconductor layer of a second conduction type arranged on the substrate, and a functional unit semiconductor layer of a third conduction type arranged on the buried semiconductor layer, in which at least two semiconductor functional units arranged laterally alongside one another are provided. The buried semiconductor layer is part of at least one semiconductor functional unit, the semiconductor functional units being electrically insulated from one another by an isolation structure which permeates the functional unit semiconductor layer, the buried semiconductor layer, and the substrate. The isolation structure includes at least one trench and an electrically conductive contact to the substrate, the contact to the substrate being electrically insulated from the functional unit semiconductor layer and the buried layer by the at least one trench.

Claims

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

providing a substrate of a first conduction type;

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

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

forming at least one trench in the semiconductor body which reaches right into the substrate;

forming an insulating layer, which covers the inner walls of the trench and electrically insulates the trench interior from the functional unit semiconductor layer and the buried semiconductor layer but has a cutout at least in the region of the trench bottom; and

filling the at least one trench with an electrically conductive material of the first conduction type, said electrically conductive material realizing an electrical contact to the substrate, completely filling the space within the trench with the electrically conductive material of the first conduction type and extending to the surface of the functional unit semiconductor layer; and

wherein the electrically conductive material is a semiconductor material; and

further comprising, prior to filling the at least one trench with the semiconductor material, introducing dopants of the first conduction 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.

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

forming a substrate of a first conduction type;

forming a buried semiconductor layer on the substrate, the buried semiconductor layer comprising at least one region whose conduction type is the first conduction type and at least one other region whose conduction type is a second conduction type;

forming a functional unit semiconductor layer on the buried semiconductor layer, said functional unit semiconductor layer containing semiconductor functional units;

forming at least one trench structure in the semiconductor body, each trench structure, proceeding from the top side of the functional unit semiconductor layer, reaching right into the substrate, and each trench structure comprising two trenches which are laterally spaced apart from one another and between which is situated the at least one region of the buried semiconductor layer with the first conduction type,

wherein the lateral positions of the trenches overlap the lateral positions of the at least one region of the buried semiconductor layer with the first conduction type, so that as a result of the formation of the trenches, the lateral extents of the at least one region of the buried semiconductor layer with the first conduction doping type are decreased, and

enlarging the vertical and/or horizontal extent of the at least one region of the buried semiconductor layer with the first conduction type by performing a heat treatment process.

3. The method of claim 2, further comprising converting the region above the region of the first conduction type of the buried semiconductor layer into a region of the first conduction type by introducing dopants.

4. The method of claim 2, further comprising filling the trenches with insulating material.