IEC TS 62607-6-5:2022

Nanomanufacturing - Key control characteristics - Part 6-5: Graphene-based materials - Contact and sheet resistance: transmission line measurement

IEC TS 62607-6-5:2022(E) establishes a standardized method to determine the key control characteristics
contact resistance, and
sheet resistance  for graphene-based materials and other two-dimensional materials by a
transmission line measurement.  The method uses test structures applied to the 2D material by photolithographic methods consisting of several metal electrodes with increasing spacing between the electrodes. By a measurement of the voltage drop between different pairs of electrodes, sheet resistance and contact resistance can be calculated.
The method can be applied to any other two-dimensional materials which are subject to electrical metal contact on top of the materials.
The method provides accurate and reproducible results, if the electrical contact formed between the two-dimensional material and the metal electrodes provides ohmic contact property.

General Information

• Status: Published
• Publication Date: 13-Dec-2022
• ICS: 07.120 - Nanotechnologies
• ICS: 17.140.20 - Noise emitted by machines and equipment
• ICS: 97.040.50 - Small kitchen appliances
• Technical Committee: TC 113 - Nanotechnology for electrotechnical products and systems
• Drafting Committee: PT 62607-6-5 - TC 113/PT 62607-6-5
• Current Stage: PPUB - Publication issued
• Start Date: 13-Jan-2023
• Completion Date: 14-Dec-2022

Standards Content (Sample)

IEC TS 62607-6-5 ®
Edition 1.0 2022-12
TECHNICAL
SPECIFICATION
colour
inside
Nanomanufacturing – Key control characteristics –
Part 6-5: Graphene-based materials – Contact resistance and sheet resistance:
transmission line measurement
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IEC TS 62607-6-5 ®
Edition 1.0 2022-12
TECHNICAL
SPECIFICATION
colour
inside
Nanomanufacturing – Key control characteristics –

Part 6-5: Graphene-based materials – Contact resistance and sheet resistance:

transmission line measurement
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 07.120 ISBN 978-2-8322-6224-5

– 2 – IEC TS 62607-6-5:2022 © IEC 2022
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 General terms . 7
3.2 Key control characteristics . 9
4 General . 10
4.1 Measurement principle . 10
4.2 Recommended sample preparation method. 11
4.3 Recommended measurement equipment and apparatus . 12
5 Measurement of sheet resistance and contact resistance . 14
5.1 Recommended measurement procedure . 14
5.2 Suggested I-V measurement to ensure ohmic contact . 15
5.3 Constraint in using TLM for Schottky contact devices . 16
6 Results to be reported (case studies) . 16
6.1 Measured results of the contact resistance and sheet resistance of graphene . 16
6.2 Measured results of the contact resistance of MoS . 18
6.3 TLM patterns for the bilayer graphene and the results obtained by the four-
point probe method . 18
Annex A (informative) Measurement results and the simulation results from various
setups . 20
Bibliography . 23

Figure 1 – TLM pattern structure . 10
Figure 2 – Determination of contact resistance and sheet resistance . 11
Figure 3 – Optical microscopy pictures of rectangular TLM channels and differently
spaced TLM electrodes defined by electron beam lithography . 12
Figure 4 – TLM structure and its equivalent circuit of two-point probe (2PP) TLM for
contact resistance and sheet resistance. 12
Figure 5 – Schematic view of four-point probe (4PP) TLM pattern for measuring
contact resistance and sheet resistance. 13
Figure 6 – Experimental setup for contact resistance and sheet resistance
measurements . 14
Figure 7 – Output curves drawn for total current (I ) as a function of voltage applied
ds
(V ) for different spacings between electrodes from a bilayer graphene TLM pattern . 15
ds
Figure 8 – Output curves drawn for total current (I ) as a function of voltage applied
ds
(V ) for different spacings between TLM electrodes from a MoS TLM pattern . 15
ds 2
Figure 9 – Resistances of graphene measured by TLM . 16
Figure 10 – Schematic views of the graphene TLM pattern where L > L > L > L >
5 4 3 2
L and optical microscopy images of the TLM pattern . 17
Figure 11 – Contact resistance of MoS device fabricated by forming benzyl viologen
(BV) polymeric interlayer. 18
Figure 12 – TLM patterns for the bilayer graphene and the results obtained by the four-
point probe method . 19

Figure A.1 – Comparison of TLM two-point probe and four-point probe setups . 21

Table 1 – Contact resistance and sheet resistance of graphene, obtained from
different plasma etching conditions . 17
Table A.1 – Contact resistance measurement by TLM and conventional four-point

probe methods based upon the case study of Figure 12 . 20
Table A.2 – Sheet resistance measurement by TLM and conventional four-point probe
methods based upon the case study of Figure 12 . 21
Table A.3 – Simulation of contact resistance and sheet resistance results from TLM
two-point probe and four-point probe methods . 22

– 4 – IEC TS 62607-6-5:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NANOMANUFACTURING – KEY CONTROL CHARACTERISTICS –

Part 6-5: Graphene-based materials – Contact resistance and sheet
resistance: transmission line measurement

FOREWORD
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IEC TS 62607-6-5 has been prepared by IEC technical committee 113: Nanotechnology for
electrotechnical products and systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
113/677/DTS 113/709/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
available at www.iec.ch/members_experts/refdocs. The main document types developed by
IEC are described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC TS 62607 series, published under the general title
Nanomanufacturing – Key control characteristics, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
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– 6 – IEC TS 62607-6-5:2022 © IEC 2022
INTRODUCTION
Technical Specifications for contact resistance and sheet resistance of two-dimensional
materials provide a proper definition of contact resistance and sheet resistance measurement
and an electrical characterization of two-dimensional materials. This document includes
reco
...