IEC 63068-5:2026

• Abstract:

  IEC 63068-5:2026 provides definitions and guidance in use of X-ray topography inspection system for detecting defects in silicon carbide (SiC) homoepitaxial wafers. Additionally, this document exemplifies X-ray topographic images to enable the detection and categorization of defects in SiC homoepitaxial wafers.

• Status: Published
• Publication Date: 05-Oct-2026
• ICS: 31.080.99 - Other semiconductor devices
• Technical Committee: TC 47 - Semiconductor devices
• Drafting Committee: WG 5 - TC 47/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 06-Oct-2026
• Completion Date: 03-Nov-2026

IEC 63068-5:2026 is an IEC International Standard for semiconductor devices that describes a non-destructive test method for detecting defects in silicon carbide (SiC) homoepitaxial wafers for power devices. It specifies how to use X-ray topography (XRT) to recognize, classify, and report wafer defects, with guidance for the people who set up the inspection system, run the measurements, and evaluate the images.

What does IEC 63068-5:2026 specify?

IEC 63068-5:2026 specifies definitions and guidance for using an X-ray topography inspection system to detect defects in SiC homoepitaxial wafers. It also provides example XRT images so users can identify and categorize the defect patterns they see in practice.

The document is organized into:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - X-ray topography method
• Annex A - Informative examples of defect images

Annex	What it covers
Annex A	Typical XRT images and features of defects in 4H-SiC homoepitaxial wafers, with examples for defect recognition

What are the key requirements of IEC 63068-5:2026?

IEC 63068-5:2026 focuses on how to set up, run, and interpret XRT inspection so that defect recognition is repeatable and traceable. The practical emphasis is on matching the inspection conditions to the defect type, then documenting the result in a way that can be reviewed later.

Defects that XRT is meant to evaluate

Clause 4.1 states that defects in SiC homoepitaxial wafers that create strong lattice strain fields shall be evaluated by the XRT method because they produce characteristic contrast in XRT images. In practice, this means the method is intended for defect classes that can be seen as distinct dark contrasts under the right diffraction condition.

Clause 4.1 also notes that defects with insufficient contrast should be checked by other methods such as optical inspection and photoluminescence. This matters because XRT is not the right tool for every defect, so inspection plans need a complementary method when XRT contrast is too weak.

The inspection setup

Clause 4.3.1 describes a laboratory XRT imaging system as a combination of an X-ray source, X-ray optics, a goniometer system with a wafer stage, an X-ray image detection system, a controller or processor, and a radiation safety cabinet. The practical point is that image quality depends on the whole measurement chain, not just the detector.

Clause 4.3.1 also requires the X-ray source and optics to provide a beam suitable for separating the useful diffraction signal from overlapping spectral components, and the detector must have enough resolution to judge defect shape and size. That is what allows the inspector to distinguish one defect class from another instead of seeing only a blurred contrast.

Wafer positioning and measurement stability

Clause 4.3.2 requires wafers to be positioned on the X-Y stage and aligned by rotation so the image is uniform and high in intensity. Clause 4.3.3 adds that X-ray optics and incident angle must be adjusted during testing to maintain uniformity and constancy across the wafer.

In practice, this means the same wafer can be scanned across multiple locations without the image quality drifting. For production work, that is important because uneven intensity can make one area look defect-free when it is not.

Image capture, processing, and analysis

Clause 4.3.4 requires the wafer to be aligned before image acquisition and the optics to be periodically realigned using specified reference wafers. Clause 4.3.5 says the captured image shall be rescaled to the actual wafer size so the defect positions and shapes correspond to the real wafer.

Clause 4.3.6 describes three analysis routes: binary image analysis, grey-level analysis, and software using defect-recognition algorithms. Clause 4.3.7 then turns the analysis output into characteristic values through a defect classification scheme. In practice, this is the step that converts a picture into a usable defect decision.

Reference wafers and parameter setting

Clause 4.4 says test wafers should be compared with reference wafers when setting parameters. The reference wafers should be as similar as possible to the test wafers in structure and specification, ideally from the same laboratory or factory and produced with the same equipment and process.

This matters because the method depends on tuning the image-capture conditions until the defect contrast is visible in a controlled way. Using comparable reference wafers helps the user confirm that a contrast pattern really corresponds to the defect being sought.

Evaluation and reporting

Clause 4.6 says the analysis should identify the positions and types of defects, and extended defects should be counted by defect type. It also requires defect maps that show the distribution of defects across the wafer and indicate the wafer orientation flat or notch.

Clause 4.6.2 gives a way to estimate the mean width of planar and volume defects from the homoepitaxial-layer thickness and the off-cut geometry. Clause 4.8 lists the mandatory test-report items, including the number of each detected defect type, test-wafer identification, reference to IEC 63068-5, key XRT system parameters, and the test date. This gives users a record that can be reviewed in quality checks, audits, and supplier discussions.

What terms does IEC 63068-5:2026 define?

• Silicon carbide (SiC) - A semiconductor crystal made of silicon and carbon that exists in several polytypes, including 3C, 4H, and 6H.
• 4H-SiC - A hexagonal SiC crystal structure used in this document’s defect-detection examples.
• X-ray topography (XRT) - A method for assessing extended crystal defects by recording a two-dimensional intensity profile of an X-ray beam diffracted by the crystal lattice.
• XRT imaging - The technique of capturing, processing, and analysing diffraction images with an X-ray source, optics, goniometer, image sensor, and computer systems.
• Diffraction condition - The geometric condition that determines how the X-ray beam is reflected by the crystal for a selected (hkl) reflection.
• Reference wafer - A specified wafer used to set parameters and check reproducibility and repeatability of the inspection process.
• Test wafer - The semiconductor wafer under inspection for defect evaluation.
• Defect density map - An image that shows the local density of defects across the wafer as a grid map or heat map.

Who uses IEC 63068-5:2026?

IEC 63068-5:2026 is used by engineers, quality managers, and test-laboratory staff working with SiC homoepitaxial wafers for power devices. It is also relevant for production teams and suppliers who need a common method for setting up XRT inspection, classifying defects, and recording results.

In practice, users apply it when they need to:

• configure an XRT inspection system
• compare test wafers with reference wafers
• recognize defect types from XRT contrast
• create defect maps and count defects by type
• document results for quality control or review

Which standards are used with IEC 63068-5:2026?

IEC 63068-5:2026 cites IEC 63068-1 as its normative reference. IEC 63068-1 provides the defect classification framework and the terms and definitions used throughout this part.

IEC 63068-2 is listed in the bibliography and is used as the related optical-inspection test method in the same IEC 63068 series. Several terms in this part are also sourced from IEC 63068-2, so it supports the broader defect-recognition approach across the series.

What does the IEC 63068-5:2026 document contain?

IEC 63068-5:2026 contains a laboratory method description, a schematic of the XRT imaging system, image-processing and evaluation steps, and a reporting checklist. It also includes a formula-based approach for estimating the mean width of planar and volume defects from wafer and epitaxial-layer geometry.

Annex A is the practical visual guide. It gives example XRT images for micropipe, TSD, TED, BPD, scratch trace, stacking fault, and polytype inclusion, which helps users compare observed contrasts with known defect appearances.

The document is aimed at defect recognition and classification work rather than destructive inspection. That makes it useful for measurement setup, process control, and technical review of SiC homoepitaxial wafers in power-device manufacturing.

IEC 63068-5 ®
Edition 1.0 2026-10
INTERNATIONAL
STANDARD
Semiconductor devices - Non-destructive recognition criteria of defects in
silicon carbide homoepitaxial wafer for power devices -
Part 5: Test method for defects using X-ray topography
ICS 31.080.99  ISBN 978-2-8327-1535-2

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CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 X-ray topography method . 10
4.1 General . 10
4.2 Principle . 11
4.3 Requirements . 11
4.3.1 Measuring equipment . 11
4.3.2 Wafer positioning . 13
4.3.3 Uniformity and constancy. 13
4.3.4 Image capturing . 13
4.3.5 Image processing . 14
4.3.6 Image analysis . 14
4.3.7 Image evaluation . 14
4.3.8 Documentation . 14
4.4 Parameter settings . 14
4.4.1 General . 14
4.4.2 Parameter setting process . 14
4.5 Procedure . 15
4.6 Evaluation . 15
4.6.1 General . 15
4.6.2 Mean width of planar and volume defects . 15
4.6.3 Evaluation process . 15
4.7 Precision. 15
4.8 Test report . 16
4.8.1 Mandatory elements . 16
4.8.2 Optional elements . 16
Annex A (informative) X-ray topography images of defects . 17
A.1 General . 17
A.2 Micropipe . 17
A.3 TSD . 19
A.4 TED . 21
A.5 BPD . 22
A.6 Scratch trace . 24
A.7 Stacking fault . 26
A.8 Polytype inclusion . 28
Bibliography . 31

Figure 1 – Schematic diagram of laboratory XRT imaging system . 12
Figure A.1 – Example 1 of micropipe . 18
Figure A.2 – Example 2 of Micropipe . 19
Figure A.3 – Example 1 of TSD . 20
Figure A.4 – Example 2 of TSD . 21
Figure A.5 – Example of TED . 22
Figure A.6 – Example 1 of BPD . 23
Figure A.7 – Example 2 of BPD . 24
Figure A.8 – Example 1 of scratch trace. 25
Figure A.9 – Example 2 of scratch trace. 26
Figure A.10 – Example 1 of stacking fault . 27
Figure A.11 – Example 2 of Stacking fault . 28
Figure A.12 – Example 1 of Polytype inclusion . 29
Figure A.13 – Example 2 of polytype inclusion . 30

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Semiconductor devices -
Non-destructive recognition criteria of defects
in silicon carbide homoepitaxial wafer for power devices -
Part 5: Test method for defects using X-ray topography

FOREWORD
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IEC 63068-5 has been prepared by IEC technical committee 47: Semiconductor devices. It is
an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
47/2915/CDV 47/2985/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
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A list of all parts in the IEC 63068 series, published under the general title Semiconductor
devices - Non-destructive recognition criteria of defects in silicon carbide homoepitaxial wafer
for power devices, can be found on the IEC website.
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– reconfirmed,
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– revised.
INTRODUCTION
Results of evaluating defects on silicon carbide homoepitaxial wafer by test methods using
optical inspection and/or photoluminescence often depend on wafer conditions, such as surface
morphology and spatial variations in impurity concentration, and therefore often require visual
confirmation after equipment-based inspection. In particular, micropipes, TSDs, TEDs and
particle inclusions belong to different defect classes but exhibit similar visual features. Accurate
classification of these defects relies on test methods that provide complementary information,
including X-ray topography.
This part of IEC 63068 provides definitions and guidance in use of X-ray topography in detecting
defects in silicon carbide (SiC) homoepitaxial wafers.

1 Scope
This part of IEC 63068 provides definitions and guidance in use of X-ray topography inspection
system for detecting defects in silicon carbide (SiC) homoepitaxial wafers. Additionally, this
document exemplifies X-ray topographic images to enable the detection and categorization of
defects in SiC homoepitaxial wafers.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 63068-1, Semiconductor devices - Non-destructive recognition criteria of defects in silicon
carbide homoepitaxial wafer for power devices - Part 1: Classification of defects
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63068-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.1
silicon carbide
SiC
semiconductor crystal composed of silicon and carbon, which exhibits a large number of
polytypes such as 3C, 4H, and 6H
Note 1 to entry: A symbol like 4H gives the number of periodic stacking layers (2, 3, 4,…) and the crystal symmetry
(H = hexagonal, C = cubic) of each polytype.
[SOURCE: IEC 63068-1:2019, 3.1]
3.2
4H-SiC
SiC crystal showing a hexagonal symmetry, in which four Si-C layers are periodically arranged
along the crystallographic c-axis
Note 1 to entry: The crystal structure of 4H-SiC is similar to wurtzite with a unit cell having four periodical occupied
sites along the <0001> direction.
[SOURCE: IEC 63068-1:2019, 3.3]
3.3
X-ray topography
XRT
method of assessing extended defects in a crystal, where a two-dimensional intensity profile of
an X-ray beam diffracted by a crystal lattice is recorded
Note 1 to entry: The diffraction condition in X-ray topography is characterized by a diffraction vector g.
Note 2 to entry: XRT is also known as X-ray diffraction imaging (XRDI).
[SOURCE: IEC 63068-1:2019, 3.47, modified – “x-rays diffracted by a crystal” has been
replaced with “X-ray beam diffracted by a crystal lattice” and Note 2 has been added.]
3.4
XRT imaging
technique for capturing, processing and analysing diffraction images of a crystal using an X-ray
source, X-ray optics, a goniometer system, an optical image sensor and computer systems
3.5
diffraction condition
geometrical condition how an X-ray beam is reflected by a crystal, denoted as (hkl) reflection,
defined by the periodic three-dimensional arrangement of atoms in the crystal
Note 1 to entry: Scattering vector of the X-ray beam is perpendicular to the (h/n k/n l/n) plane, where n is the greatest
common divisor of h, k, and l.
Note 2 to entry: In 4H-SiC showing a hexagonal symmetry, four-digit indices, hkil, are frequently used, where h + k
+ i = 0.
3.6
X-ray source
system which generates and emits X-rays, comprising a high-voltage power supply unit and an
X-ray tube consisting of a vacuum cavity containing a target material and a filament
Note 1 to entry: The X-ray source for a laboratory system uses simple substance such as copper as a target
material.
3.7
characteristic X-ray beam
X-ray beam showing the line spectrum of wavelengths unique to the constituent elements of the
target material
3.8
X-ray optics
optical components which shape and filter an X-ray beam that travels to a test wafer
3.9
crystal monochromator
X-ray optic to select a defined wavelength of the X-ray beam for further purpose on a dedicated
instrument
3.10
multilayer collimating mirror
X-ray optic having a multilayer structure that filters wavelength of X-rays and collimates the
beam
3.11
slit
X-ray optic with a very narrow opening to limit the size of an X-ray beam
3.12
goniometer
device to precisely control the relative angle between an X-ray source, a test wafer, and an
X-ray detector
3.13
X-ray detector
device that converts X-ray photons into an electric or chemical signal in order to monitor X-ray
intensity
3.14
X-ray film
film coated with a silver halide emulsion that records X-ray radiation
3.15
nuclear emulsion plate
high-sensitivity X-ray film in which very small and uniform silver halide particles of emulsion are
applied densely and thickly
3.16
CCD image sensor
light-sensitive integrated circuit chip which converts detected photons to electric signals
3.17
CMOS image sensor
light-sensitive integrated circuit chip with MOSFETs and logic gates which converts detected
photons to electric signals
3.18
scintillator
material which converts X-rays to photons whose energy is detectable by sensors through
fluorescence
3.19
strain field
deviation from the atomic arrangement of a perfect crystal due to defects
3.20
penetration depth
vertical length from the wafer surface where an X-ray beam can probe the crystallographic
features
3.21
image capturing
process of creating a two-dimensional original digital image of defects in the wafer
3.22
pixel
smallest formative element of original digital images, to which a grey level is assigned
[SOURCE: IEC 63068-2:2019, 3.16]
3.23
resolution
number of pixels per unit length (or area) of the original digital images
Note 1 to entry: If the resolutions in the X- and Y-directions are different, both values are typically recorded.
[SOURCE: IEC 63068-2:2019, 3.17]
3.24
grey level
degree of brightness defined in a greyscale assigned to each pixel which corresponds to the
X-ray intensity
Note 1 to entry: It is conventional to invert a digital image so that higher diffracted intensity is darker, as is the case
with film exposures.
3.25
contrast
difference between the grey levels of two specified parts of a topographic image
3.26
image processing
software manipulation of original digital images to prepare for subsequent image analysis
Note 1 to entry: For example, image processing can be used to eliminate errors generated during image capturing
or to reduce image information to the essential.
[SOURCE: IEC 63068-2:2019, 3.20, modified – The word “mistakes” has been replaced with
“errors” in the Note.]
3.27
binary image
image in which either 0 (white) or 1 (black) is assigned to each pixel
[SOURCE: IEC 63068-2:2019, 3.21, modified – “0 (black) or 1 (white)” has been replaced with
“0 (white) or 1 (black)”.]
3.28
thresholding
image analysis procedure where each pixel value is converted into either 0 (white) or 1 (black)
by setting a given threshold to segment the image into regions with and without defects
[SOURCE: IEC 63068-2:2019, 3.25, modified – The definition has been entirely modified and
the note has been removed.]
3.29
image analysis
extraction of information from processed digital images and classification of defects
3.30
image evaluation
process of relating a series of values resulting from image analysis of one or more characteristic
images via a classification scheme of defects
[SOURCE: IEC 63068-2:2019, 3.27]
3.31
grey-level analysis
image analysis procedure where grey levels of segments are compared and classified into
distinct defects
3.32
defect density map
image showing local density of defects on a wafer in a grid map or a heat map
3.33
reference wafer
specified wafer used for parameter settings, which has already been evaluated for checking the
reproducibility and repeatability of inspection process for defects
[SOURCE: IEC 63068-2:2019, 3.28, modified – The expression “optical inspection” has been
replaced with “inspection”.]
3.34
test wafer
semiconductor wafer under test to evaluate defects
4 X-ray topography method
4.1 General
Defects in SiC homoepitaxial wafer, which induce strong lattice strain fields as defined in
IEC 63068-1, shall be evaluated by XRT method since they show characteristic contrast in XRT
images. The following descriptions concern such defects in n/n+-type 4H-SiC homoepitaxial

wafers with an off-cut angle of 4° along the direction of 1120 , where their XRT images are

obtained by scanning the X-ray beam diffracted by (008) reflection and/or (118) reflection
(conventionally (0008) reflection and/or 1128 reflection) using a laboratory XRT imaging
( )
system:
– individual defects exhibiting dark spots, e.g. micropipes (Figure A.1 a
...