GB/T 43894.2-2026Practice for determining semiconductor wafer near-edge geometry - Part 2: Roll-off amount (ROA) (English PDF)

1 Scope

This document describes a method for evaluating the near-edge geometry of semiconductor wafers using the edge curling (ROA) method.

This document applies to 300mm diameter polished silicon wafers, silicon epitaxial wafers, silicon-on-insulator (SOI) wafers, and other circular wafers with surface layers.

This method is also applicable to the evaluation of the near-edge geometry of circular wafers made of other semiconductor materials.

Note. Refer to this document for.200mm diameter silicon wafers.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 14264-2024 Semiconductor Materials Terminology

GB/T 16596 Specification for Determining Wafer Coordinate Systems

GB/T 25915.1-2021 Cleanrooms and related controlled environments – Part 1.Classification of air cleanliness levels by particle concentration

3 Terms and Definitions

The terms and definitions defined in GB/T 14264-2024, as well as the following terms and definitions, apply to this document.

4 Principles

Height data arrays were acquired at different angles and in the radial direction. A baseline was fitted based on the edge curling data within the reference area, and the data were calculated one by one.