IEC 63068-4:2022

Overview

IEC 63068-4:2022 defines a non-destructive, reproducible procedure for identifying and evaluating defects in as-grown 4H‑SiC homoepitaxial wafers used for power devices. The standard prescribes a combined method that systematically integrates optical inspection and photoluminescence (PL) imaging to improve accuracy of defect recognition versus single-method inspection. It also includes exemplar optical and PL images (Annex A) to help categorize common defect types such as micropipes, stacking faults, TSD/TED, BPD, particle inclusions and surface scratches.

Key Topics

• Combined inspection principle: capture both optical and PL images, convert images to digital grey-scale (or color), then to binary for analysis.
• Image analysis: measure defect size, shape and mean width (planar/volume defects); compute distribution and defect density within specified wafer areas.
• Parameter setting and procedure: defined steps for configuring imaging and analysis parameters, with a parameter-setting process to ensure reproducibility.
• PL specifics: examples use emissions detected at wavelengths longer than 650 nm; PL images can show enlarged defect footprints due to carrier diffusion in SiC epilayers.
• Limitations and cross-checks: some defects produce similar visual features in a single method-IEC 63068-4 recommends combining methods and, when necessary, additional techniques (e.g., X‑ray) to resolve ambiguity.
• Reporting and precision: the standard specifies precision requirements and mandatory/optional elements for the test report to support traceability and quality control.
• Illustrative annex: Annex A provides optical and PL image examples for defect recognition and classification.

Applications

Who uses IEC 63068-4:2022 and why:

• SiC wafer manufacturers and epitaxy process engineers: to detect and classify as-grown defects and improve epitaxial process control.
• Power device fabs and quality engineers: for incoming wafer inspection, yield improvement and acceptance criteria based on non-destructive recognition.
• Failure analysis and R&D teams: to correlate defect types with device performance and explore mitigation strategies.
• Inspection equipment vendors and test labs: to validate and calibrate combined optical + PL inspection systems against an international procedure. Practical benefits include more accurate defect detection, improved reproducibility, standardized reporting, and better alignment between inspection results and device yield.

Related Standards

• IEC 63068-1 - Classification of defects
• IEC 63068-2 - Test method using optical inspection
• IEC 63068-3 - Test method using photoluminescence

Using IEC 63068-4:2022 supports consistent, non-destructive wafer inspection practices for silicon carbide (SiC) power device manufacturing and quality assurance.