Semiconductor wafer of monocrystalline silicon and method of producing the semiconductor wafer

Patent metadata

Field	Value
Publication number	US-11417733-B2
Application number	US-201816636352-A
Country	US
Kind code	B2
Filing date	Jul 19, 2018
Priority date	Aug 4, 2017
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

Epitaxially coated semiconductor wafers of monocrystalline silicon comprise a p+-doped substrate wafer and a p-doped epitaxial layer of monocrystalline silicon which covers an upper side face of the substrate wafer;an oxygen concentration of the substrate wafer of not less than 5.3×1017 atoms/cm3 and not more than 6.0×1017 atoms/cm3;a resistivity of the substrate wafer of not less than 5 mΩcm and not more than 10 mΩcm; andthe potential of the substrate wafer to form BMDs as a result of a heat treatment of the epitaxially coated semiconductor wafer, where a high density of BMDs has a maximum close to the surface of the substrate wafer.

First claim

The invention claimed is:

1. An epitaxially coated semiconductor wafer of monocrystalline silicon, comprising:
a p + -doped substrate wafer;
a p-doped epitaxial layer of monocrystalline silicon which covers an upper face of the substrate wafer;
an oxygen concentration of the substrate wafer of not less than 5.3×10 17 atoms/cm 3 and not more than 6.0×10 17 atoms/cm 3 ;
a resistivity of the substrate wafer of not less than 5 mΩcm and not more than 10 mΩcm; and
a potential of the substrate wafer to form BMDs (bulk microdefects) as a result of a two-stage heat treatment of the epitaxially coated semiconductor wafer, where the density of BMDs has a maximum of not less than 2×10 10 /cm 3 , the distance of the maximum from a front side of the epitaxially coated semiconductor wafer is not greater than 20 μm, and the ratio of the densities of BMDs at a distance of 20 μm and at a distance of 60 μm from the front side of the epitaxially coated semiconductor wafer is not less than 5, and the two-stage heat treatment is effected at 850° C. over a period of one hour in oxygen and at 1000° C. over a period of one hour in oxygen.

2. The epitaxially coated semiconductor wafer of claim 1 , wherein the epitaxial layer has a thickness of not less than 1 μm and not more than 5 μm.

3. The epitaxially coated semiconductor water of claim 1 , having a denuded zone having a thickness of not less than 3 μm and not more than 7 μm.

4. The epitaxially coated semiconductor wafer of claim 2 , having a denuded tone having a thickness of not less than 3 μm and not more than 7 μm.

Assignees

• Siltronic Ag

Inventors

• Sattler Andreas
• Vollkopf Alexander
• Mangelberger Karl

Classifications

• H10P14/3458

  Monocrystalline · CPC title

• H10P14/3444

  P-type · CPC title

• H10P14/3411 Primary

  Silicon, silicon germanium or germanium · CPC title

• H10P14/2924

  Structures · CPC title

• H10P14/2905 Primary

  Silicon, silicon germanium or germanium · CPC title