IEC 63068-2:2019

Overview

IEC 63068-2:2019 specifies a non-destructive optical inspection test method for detecting as-grown defects in commercially available 4H‑SiC homoepitaxial wafers used for power devices. Part 2 of the IEC 63068 series provides definitions, required practices, and illustrative optical images to support consistent identification and categorization of wafer defects using optical imaging. Destructive techniques (for example, preferential etching) are explicitly out of scope.

Keywords: IEC 63068-2, silicon carbide, 4H‑SiC, optical inspection, wafer defects, non-destructive testing, homoepitaxial wafer, power devices.

Key Topics and Requirements

• Definitions and terminology for optical inspection and imaging modes (bright‑field, dark‑field, differential interference contrast, polarized light).
• Optical inspection method fundamentals: principles of reflective illumination and imaging for defect visibility.
• Equipment and setup requirements:
  • Illumination recommendations (directional vs. diffused lighting).
  • Wafer positioning, focusing and motion control for reliable scanning.
  • Optical components and image sensor considerations.
• Image workflow:
  • Image capturing, processing, analysis and evaluation steps.
  • Parameter setting process and documentation of parameter choices.
• Evaluation and reporting:
  • Procedures for measuring defect attributes (e.g., mean width of planar/volume defects).
  • Precision considerations and required content of the test report.
• Annex of exemplar images: optical examples of common defects such as micropipes, TSD/TED, basal plane dislocations (BPD), stacking faults (and complexes), polytype inclusions, particle inclusions, scratch traces and bunched‑step segments to aid recognition.

Practical Applications and Who Uses This Standard

IEC 63068-2 is designed for organizations involved in SiC wafer production, device fabrication and quality assurance:

• SiC wafer manufacturers for in‑process and final inspection to reduce yield loss.
• Power device manufacturers (SiC MOSFETs, diodes) for incoming wafer acceptance and supplier qualification.
• Metrology and inspection labs implementing standardized optical imaging methods.
• R&D and process engineers developing epitaxy and defect mitigation strategies.
• Quality and reliability teams using non‑destructive criteria to correlate optical defects with device performance and long‑term reliability.

Practical uses include incoming inspection, supplier agreements, process control, yield improvement initiatives and validation of non‑destructive inspection equipment.

Related Standards

• IEC 63068 series (general title: Non‑destructive recognition criteria of defects in SiC homoepitaxial wafer for power devices)
  • Part 1: Classification of defects
  • Part 3: Test method for defects using photoluminescence

Using IEC 63068-2 supports consistent defect detection and communication across the SiC power device supply chain and helps accelerate adoption of silicon carbide in high‑voltage, high‑efficiency power electronics.