International ISO Standard ISO 5618-2 Fine ceramics (advanced ceramics. First edition 2024-04 advanced technical ceramics) Test method for GaN crystal surface defects Part 2: Method for determining etch pit density Ceramiques techniques -Methode d'essai pour les defauts de surface des cristaux de GaN- Partie 2:Methode dedétermination de ladensite despiqures Referencenumber ISO 5618-2:2024(en) O ISO2024 ISO 5618-2:2024(en) COPYRIGHT PROTECTED DOCUMENT OISO2024 All rights reserved.Unless otherwise specified,or required in the contextof its implementation,no part of this publication may be reproduced or utilized otherwise in any form or by any means,electronic or mechanical,including photocopying,or posting on the internet or an intranet,without prior written permission.Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office CP. 401-Ch.de Blandonnet 8 CH-1214 Vernier,Geneva Phone:+41227490111 Email:[email protected] Website:www.iso.org Published in Switzerland O ISO 2024-All rights reserved ii IS05618-2:2024( en) Contents Page Foreword IV Introduction 1 Scope 2 Normative references 3 Terms and definitions 4 Principle 5 Definition of substrate in -plane position 6 Procedures for formingan etch pit 6.1 Pre - treatment ofa sample 6.2 Etching process 6.3 Washing- 7 Method of capturing an etch pit image 7.1 Setting the observation conditions for an optical microscope 7.1.1 Objectivelens 7.1.2 Image resolution Measurement 7.1.3 area 7.1.4 Measurement points 7.2 Capturing an etch pit image byusing an optical microscope 8 Method of calculating the etch pitdensity 8.1 Etch pit counting criteria 8.1.1 Counting targets 8.1.2 Counting criteria 8.2 Counting etch pits 8 8.3 Method of calculating the etch pit density 8.4 Method of calculating the coefficientofvariation forthe etchpit density 9 Categorisingthe invertedhexagonalpyramidal etch pits bysize and calculatingtheir percentages 9 9.1 Judging whether inverted hexagonal pyramidal pitscanbe categorized by size 9 9.2 Principle of categorizing dislocations by inverted hexagonal pyramidal pit size 9.3 Determining the inverted hexagonal pyramidal pit sizes 9.4 Creatinga histogram for the inverted hexagonal pyramidal pit sizes 10 9.4.1 Setting data sections 10 9.4.2 Generating a histogram .10 9.5 Analysing a histogram 9.5.1 Method of analysing a histogram 9.5.2 Number ofinverted hexagonal pyramidalpit size levels 12 9.5.3 Inverted hexagonal pyramidal pit size levels 12 9.5.4 Method of calculatingthe percentageof an inverted hexagonal pyramidal pit size level 13 10 Test report 13 AnnexA(normative)Verification of dislocationdetection by etching 14 AnnexB(informative)Appropriate invertedhexagonal pyramidal pitsize for etch pit counting ..17 Annex C(normative)Measurement 19 Annex D(normative)Measurement points 2 Annex E(normative)Verificationof theclassifying dislocations by etch pit size 23 Bibliography 25 OISO2024-Allrightsreserved ii