IEC TS 61994-4-4:2018

IEC TS 61994-4-4 ®
Edition 3.0 2018-11
TECHNICAL
SPECIFICATION
Piezoelectric, dielectric and electrostatic devices and associated materials for
frequency control, selection and detection – Glossary –
Part 4-4: Piezoelectric materials – Single crystal wafers for surface acoustic
wave (SAW) devices
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TS 61994-4-4 ®
Edition 3.0 2018-11
TECHNICAL
SPECIFICATION
Piezoelectric, dielectric and electrostatic devices and associated materials for

frequency control, selection and detection – Glossary –

Part 4-4: Piezoelectric materials – Single crystal wafers for surface acoustic

wave (SAW) devices
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 01.040.31; 31.140 ISBN 978-2-8322-6178-1

– 2 – IEC TS 61994-4-4:2018 © IEC 2018
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 There are no normative references in this document.Terms and definitions . 5
3.1 Single crystals for SAW wafer . 5
3.2 Terms and definitions related to LN and LT crystals . 6
3.3 Terms and definitions related to all crystals . 7
3.4 Flatness . 7
3.5 Definitions of appearance defects . 10
3.6 Other terms and definitions . 11
Bibliography . 14

Figure 1 – Example of site distribution for LTV measurement . 7
Figure 2 – LTV value of each site . 8
Figure 3 – Schematic diagram of Sori . 9
Figure 4 – Wafer sketch and measurement points for TV5 determination . 9
Figure 5 – Schematic diagram of TTV . 10
Figure 6 – Schematic diagram of warp . 10

Table 1 – Description of wafer orientations . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PIEZOELECTRIC, DIELECTRIC AND ELECTROSTATIC DEVICES
AND ASSOCIATED MATERIALS FOR FREQUENCY CONTROL, SELECTION
AND DETECTION – GLOSSARY –
Part 4-4: Piezoelectric materials – Single crystal wafers
for surface acoustic wave (SAW) devices

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in
addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses
arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In exceptional
circumstances, a technical committee may propose the publication of a technical specification
when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide whether
they can be transformed into International Standards.
IEC TS 61944-4-4, which is a technical specification, has been prepared by IEC technical
committee 49: Piezoelectric, dielectric and electrostatic devices and associated materials for
frequency control, selection and detection.

– 4 – IEC TS 61994-4-4:2018 © IEC 2018
This third edition of IEC 61994-4-4 cancels and replaces the second edition published in 2010.
This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the new terms and definitions given in IEC 62276:2016 have been taken into account;
b) the general title has been changed according to the change in the title of TC 49 in 2009.
c) the part title has been changed according to the title of IEC 62276:2016.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
49/1283/DTS 49/1287/RVC
Full information on the voting for the approval of this technical specification can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61994 series, published under the general title Piezoelectric,
dielectric and electrostatic devices and associated materials for frequency control, selection and
detection – Glossary, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://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.
A bilingual version of this publication may be issued at a later date.

PIEZOELECTRIC, DIELECTRIC AND ELECTROSTATIC DEVICES
AND ASSOCIATED MATERIALS FOR FREQUENCY CONTROL, SELECTION
AND DETECTION – GLOSSARY –
Part 4-4: Piezoelectric materials – Single crystal wafers
for surface acoustic wave (SAW) devices

1 Scope
This part of IEC 61994 gives the terms and definition for single crystal wafers for surface
acoustic wave (SAW) devices representing the state of the art.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Single crystals for SAW wafer
3.1.1
as-grown synthetic quartz crystal
right-handed or left-handed single crystal quartz grown hydrothermally
[SOURCE: IEC 62276:2016, 3.1.1, modified – Notes 1 and 2 to entry have been removed.]
3.1.2
lanthanum gallium silicate
LGS
Ga SiO , grown by Czochralski
single crystals described by the chemical formula to La
3 5 14
(crystal pulling from melt) or other growing methods
[SOURCE: IEC 62276:2016, 3.1.5]
3.1.3
lithium niobate
LN
single crystals approximately described by chemical formula LiNbO , grown by Czochralski
(crystal pulling from melt) or other growing methods

– 6 – IEC TS 61994-4-4:2018 © IEC 2018
[SOURCE: IEC 62276:2016, 3.1.2]
3.1.4
lithium tantalate
LT
single crystals approximately described by chemical formula LiTaO , grown by Czochralski
(crystal pulling from melt) or other growing methods
[SOURCE: IEC 62276:2016, 3.1.3]
3.1.5
lithium tetraborate
LBO
single crystals described by the chemical formula to Li B O , grown by Czochralski (crystal
2 4 7
pulling from melt), vertical Bridgman, or other growing methods
[SOURCE: IEC 62276:2016, 3.1.4]
3.2 Terms and definitions related to LN and LT crystals
3.2.1
c
...