SEMI M40 - Guide for Measurement of Roughness of Planar Surfaces on Polished Wafers

Volume(s): Materials
Language: English
Type: Single Standards Download (.pdf)

This Standard was technically approved by the Silicon Wafer Global Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on August 25, 2014. Available at and in November 2014; originally published February 2000; previously published November 2009.


This Guide provides procedures for specifying the measurements to be used in characterizing and reporting roughness of the planar surfaces of polished wafers of silicon, various compound semiconductors, sapphire, and other types of planar wafer materials. It should be noted that the roughness of polished surfaces of silicon wafers, such as those specified in SEMI M1, various compound semiconductor wafers, and sapphire wafers, such as those specified in SEMI HB1 is generally in the microroughness range.


This Guide provides nomenclature and procedures for roughness determination that employ three key methodologies:

Standardized scan site patterns,

Roughness abbreviations, and

Reference test methodologies with respect to identifying specific roughness measurements.


This Guide incorporates the following methodologies:

Standardized scan patterns for both local and full-area surface characterization,

A set of roughness abbreviations that describe measurement conditions in a short-hand code, and

Reference test methodologies for three generic types of roughness measuring instruments. These general categories may include, but are not limited to:

  • Profilometers — AFM and other scanning probe microscopes; optical profilometers; high-resolution mechanical stylus systems,
  • Interferometers — Interference microscopes, and
  • Scatterometers — Total integrating scatterometers (TIS), angle-resolved light scatterometers (ARLS), scanning surface inspection systems (SSIS).

Procedures to obtain a representative value of roughness for a surface are specified.


Roughness nomenclature is intended to remove ambiguities with respect to identifying the roughness measurements used and the results achieved.


Referenced SEMI Standards

SEMI E89 — Guide for Measurement System Analysis (MSA)
SEMI M1 — Specifications for Polished Single Crystal Silicon Wafers
SEMI M20 — Practice for Establishing a Wafer Coordinate System
SEMI M50 — Test Method for Determining Capture Rate and False Count Rate

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