IEC TS 62607-6-4:2024
Nanomanufacturing - Key control characteristics - Part 6-4: Graphene-based materials - Surface conductance: non-contact microwave resonant cavity method

Standard No.

IEC TS 62607-6-4:2024

Release Date

2024

Published By

International Electrotechnical Commission (IEC)  IX  /  IEC

Latest

IEC TS 62607-6-4:2024

Introduction

Overview of the Standard Technical Specification

IEC TS 62607-6-4:2024 Edition 2.0 is a technical specification for critical control characteristics of nanomanufacturing, published by the International Electrotechnical Commission. It specifically addresses the surface conductivity measurement of graphene-based materials. This standard establishes a standardized measurement method based on the non-contact microwave resonant cavity method, applicable to graphene materials produced by various processes, including chemical vapor deposition, silicon carbide epitaxial growth, reduced graphene oxide, and mechanical exfoliation.

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Core Technical Principles and Measurement Mechanism

The microwave resonant cavity measurement method, based on cavity perturbation theory, calculates the surface conductivity of a material by monitoring the resonant frequency shift and quality factor change caused by the sample's insertion into the microwave cavity. The key advantage of this method lies in its non-contact measurement, which avoids the measurement errors caused by electrode contact in traditional DC measurements and more accurately reflects the material's intrinsic electrical properties.

Measurement parameters	Traditional DC method	Microwave resonant cavity method	Technical advantages
Measurement method	Contact	Non-contact	Avoid the influence of contact resistance
Measurement speed	Slow	Fast	Suitable for online quality control
Scope of application	Limited	1 S to 10-5 Wide Dynamic Range Thickness Dependence Requires Known Thickness Independent of Thickness Simplified Measurement Process Compared to the first edition in 2016, the 2024 second edition has undergone significant technical revisions: the document title has been changed from "Graphene - Surface Conductivity Measurement Using a Resonant Cavity" to "Graphene-Based Materials - Surface Conductivity: Non-Contact Microwave Resonant Cavity Method" to more accurately reflect the scope of application of the standard. Figures 1 and 2 have also been updated to better illustrate the basic principles and implementation details of the method, enhancing the standard's understandability and practicality. Measurement System Composition and Technical Requirements Microwave Cavity Test Structure The standard specifies the use of an R100 rectangular waveguide (known as WR-90 in some countries) as the resonant cavity base structure, with a typical operating frequency of 7.5 GHz. The cavity is terminated at both ends by near-zero-impedance walls, forming a standing wave field in the TE10n mode. The sample is inserted at the center of the cavity, where the electric field intensity reaches its maximum. Test Sample Requirements The test sample consists of a graphene layer coated or bonded onto a non-conductive substrate. A 200-250 μm thick electronic-grade fused silica wafer is recommended as the substrate material to minimize the substrate's impact on the measurement. Typical sample dimensions are 3 mm × 20 mm, and both the coated sample and the uncoated substrate must be measured. Measurement Procedure and Data Processing Calibration and Initialization Before measurement, a two-port full calibration must be performed on the coaxial end of the vector network analyzer using an appropriate short-open-load calibration kit. The typical values of the cavity quality factor Q0 and resonant frequency f0 are 3200 and 7.5 GHz, respectively, with a measurement uncertainty ΔQ of ±5.0. Sample insertion measurement was performed by inserting the sample in steps and recording the insertion length hx to measure the corresponding resonant frequency fx and quality factor Qx. The surface conductivity was calculated as follows: σs = [π/(2ε0f0V0)] × [w hx/(1/Qx - 1/Q0)], where ε0 is the vacuum permittivity and V0 is the cavity volume. Precision Analysis and Uncertainty Assessment Measurement accuracy is affected by multiple factors, including instrumentation, sample geometry uncertainty, roughness, and impurities. The S21 standard uncertainty of a vector network analyzer is approximately ±0.01 dB (amplitude) and ±0.5° (phase). With 800 data points, the resonant frequency can be determined to within a few kilohertz, and the relative uncertainty of the Qx factor is typically less than 0.5%. The combined relative standard uncertainty is typically better than 1%. Source of uncertainty Degree of influence Control measures Typical value Instrument accuracy Major Regular calibration ±0.01 dB Sample size Medium Precision machining ±1 Cavity Stability Minor Temperature Control ±0.1°C Data Processing Minor Algorithm Optimization <0.1% Application Cases and Experimental Results Annex A of the standard provides case studies of surface conductivity measurements of single-layer and few-layer graphene. The experimental results show that the surface conductivity of chemical vapor deposition-grown single-layer graphene is 1.84×10-3 S (corresponding to a sheet resistance of 543 Ω), and that of few-layer graphene is 7.19×10-3 S (corresponding to a sheet resistance of 139 Ω). The surface conductivity of the fused silica substrate is approximately 5.1×10-7 S, validating the effectiveness of the measurement method. Implementation Recommendations and Best Practices Equipment Selection Recommendations A two-port vector network analyzer with a dynamic range of at least 70 dB and an operating frequency range of 6-13 GHz is recommended. The waveguide's voltage-reflection standing wave ratio should be better than 1.04:1, and the insertion loss should be less than 0.5 dB/m. The sample positioning system requires micron-level precision to ensure accurate control of the insertion depth. Measurement Environment Requirements Measurements should be performed in a temperature-stable laboratory environment to avoid electromagnetic interference. A shielded room or Faraday cage is recommended to ensure repeatable and accurate measurement results. System performance should be regularly verified using standard reference materials to establish a quality control system. Data Processing Optimization A linear fitting method was used to process the relationship between (1/Qx - 1/Q0) and (w hx), and the surface conductivity was calculated from the slope. For highly conductive samples, measurement should be stopped when Qx drops to approximately 100 or the resonant peak height drops to approximately 10 dB above the noise level. Technology Development Trends and Standardization Outlook With the deepening of two-dimensional material research and the expansion of industrial applications, non-contact microwave measurement technology will play an increasingly important role in the quality control of graphene-based materials. Future standard development directions may include higher frequency measurement methods, simultaneous multi-parameter measurement techniques, and integration with other characterization methods to provide more comprehensive solutions for the nanomanufacturing industry. IEC TS 62607-6-4:2024 history 2024 IEC TS 62607-6-4:2024 Nanomanufacturing - Key control characteristics - Part 6-4: Graphene-based materials - Surface conductance: non-contact microwave resonant cavity method Topics on standards and specifications Barite 6 microns Standard and Specification IEC TS 62607-6-7:2023 Nanomanufacturing - Key control characteristics - Part 6-7: Graphene - Sheet resistance: van der Pauw method IEC TS 62607-6-8:2023 Nanomanufacturing - Key control characteristics - Part 6-8: Graphene - Sheet resistance: In-line four-point probe IEC TS 62607-6-12:2024 Nanomanufacturing - Key Control Characteristics - Part 6-12: Graphene - Number of layers: Raman spectroscopy, optical reflection IEC TS 62607-6-30:2024 Nanomanufacturing. Key control characteristics - Graphene-based material. Anion concentration: Ion chromatography method BS PD IEC TS 62607-6-1:2020 Nanomanufacturing. Key control characteristics-Graphene-based material. Volume resistivity: four probe method GSO IEC 61338-1-3:2014 Waveguide type dielectric resonators - Part 1-3: General information and test conditions - Measurement method of complex relative permittivity for dielectric IEC 61338-1-3:1999 Waveguide type dielectric resonators - Part 1-3: General information and test conditions - Measurement method of complex relative permittivity for dielectric BS EN 61338-1-3:2000 Waveguide type dielectric resonators.. General information and test conditions. Measurement method of complex relative permittivity for dielectric resonator IEC TS 62607-6-5:2022 Nanomanu facturing – Key control characteristics – Part 6-5: Graphene-based materials – Contact resistance and sheet resistance: transmission line measurement Copyright ©2026 All Rights Reserved Update: Sat, 07 Feb 2026 01:38:36 +0000