ASTM E2244-11 (2018) PDF

Full title and description

Designation: ASTM E2244-11 (Reapproved 2018) — Standard Test Method for In-Plane Length Measurements of Thin, Reflecting Films Using an Optical Interferometer. The standard describes a laboratory test method for measuring in-plane lengths (including deflections) of patterned thin, reflecting films (for example those found in MEMS) using a non-contact optical interferometric microscope that produces topographical 3‑D data sets.

Abstract

ASTM E2244-11(2018) specifies procedures and measurement considerations for obtaining in-plane length and deflection measurements of thin, reflecting films via optical interferometry. It explains significance and use (e.g., inputs to residual strain and Young’s modulus calculations), instrument and measurement limits (field of view and pixel spacing), and calibration/uncertainty considerations. The document was reapproved in 2018 and subsequently withdrawn by ASTM in November 2023.

General information

• Status: Withdrawn (withdrawal effective 02-Nov-2023).
• Publication date: Reapproved / current edition effective 01-May-2018 (originally approved 2011).
• Publisher: ASTM International.
• ICS / categories: 37.040.20 (Photographic paper, film and plates; related measurement terminology for thin reflecting films).
• Edition / version: E2244-11 (Reapproved 2018).
• Number of pages: 14 pages.

Scope

This test method covers procedures for measuring in-plane lengths and deflections of patterned thin, reflecting films that can be imaged using an optical interferometer (interferometric microscope). It applies when interferometric measurement is preferred over design dimensions (for example when measuring small in-plane deflections or when the fabrication process is unproven). The standard notes instrument constraints (maximum measurable in-plane length set by the interferometer field of view at low magnification; minimum detectable deflection determined by pixel spacing at high magnification) and identifies that the method is intended for laboratory use.

Key topics and requirements

• Use of non-contact optical interferometric microscopes to obtain topographical 3‑D data sets for in-plane length and deflection measurements.
• Procedures for extracting in-plane length/deflection from 3‑D interferometric data (2‑D traces and point groups).
• Calibration and uncertainty considerations (including pixel spacing, alignment, and standard deviation calculations for ruler measurements).
• Instrument limits: field-of-view (max in-plane length) and pixel-to-pixel spacing (min deflection resolution).
• Application to MEMS test structures and interpretation of measurements for derived parameters (residual strain, Young’s modulus, strain gradients when used with companion standards).
• Reference and cross‑reference to companion test methods and terminology standards for residual strain and strain-gradient measurements and for terminology used with thin reflecting films.

Typical use and users

Primary users include MEMS and microfabrication researchers, metrology and characterization laboratories, semiconductor and MEMS device manufacturers, and standards bodies. Typical uses are measuring small in-plane deflections of patterned thin-film structures, validating fabrication process dimensions, and providing measured inputs for computations of residual strain and mechanical properties of thin films. The method is intended for laboratory environments where interferometric microscopes are available and when non-contact high-precision measurements are required.

Related standards

Closely related ASTM standards include E2245 (Residual Strain Measurements of Thin, Reflecting Films Using an Optical Interferometer), E2246 (Strain Gradient Measurements of Thin, Reflecting Films Using an Optical Interferometer) and terminology standard E2444 (Terminology Relating to Measurements Taken on Thin, Reflecting Films). Historical and ancillary references (e.g., older E2245/E2246 editions and certain AFM calibration practices) are cited within the standard.

Keywords

in‑plane length, interferometric microscope, optical interferometer, thin reflecting films, MEMS, deflection measurement, residual strain, strain gradient, calibration, measurement uncertainty, metrology

FAQ

Q: What is this standard?

A: ASTM E2244-11 (Reapproved 2018) is a test method that defines how to measure in‑plane lengths and deflections of thin, reflecting films using an optical interferometer (interferometric microscope).

Q: What does it cover?

A: It covers laboratory procedures for acquiring and extracting in‑plane dimensional and deflection data from topographical 3‑D interferometric data sets, calibration/uncertainty considerations, and instrument limitations (field of view and pixel spacing).

Q: Who typically uses it?

A: MEMS researchers, microfabrication/metrology labs, device manufacturers, and engineers performing thin‑film mechanical characterization or validating fabrication processes.

Q: Is it current or superseded?

A: The standard was reapproved in 2018 (edition E2244-11, effective 01-May-2018) but was withdrawn by ASTM with an effective withdrawal date of 02-Nov-2023; the withdrawal notice indicates it was withdrawn without replacement due to limited industry use. Users should consult ASTM International for any newer guidance or replacements.

Q: Is it part of a series?

A: Yes — E2244 is part of a set of related test methods and terminology for thin, reflecting films measured by interferometry; companion documents include E2245 (residual strain), E2246 (strain gradient), and terminology standard E2444.

Q: What are the key keywords?

A: in‑plane measurement, interferometry, interferometric microscope, thin reflecting film, MEMS, deflection, residual strain, measurement uncertainty.