1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationSemiconductor devicesPart 1: Time-dependent dielectric breakdown (TDDB) test for inter-metal layersBS EN 62374-1:2010Incorporating corrigendum April 2011National forewordThis Bri
2、tish Standard is the UK implementation of EN 62374-1:2010,The UK participation in its preparation was entrusted to Technical Committee EPL/47, Semiconductors.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include
3、 all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 75206 3 ICS 31.080.01Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Polic
4、y and Strategy Committee on 31 December 2010.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 62374-1:2010incorporating corrigendum April 2011. It is identical to IEC 62374-1:2010. 30 June 2011 Implementation of CENELEC corrigendum April 2011: supersession detail
5、s deletedEUROPEAN STANDARD EN 62374-1 NORME EUROPENNE EUROPISCHE NORM November 2010 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels
6、2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62374-1:2010 E ICS 31.080 Incoporating corrigendum April 2011English version Semiconductor devices - Part 1: Time-dependent dielectric breakdown (TDDB) test for inter-metal laye
7、rs (IEC 62374-1:2010) Dispositifs semiconducteurs - Partie 1: Essai de rupture dilectrique en fonction du temps (TDDB) pour les couches intermtalliques (CEI 62374-1:2010) Halbleiterbauelemente - Teil 1: Prfung auf zeitabhngigen dielektrischen Durchbruch (TDDB) bei Isolationsschichten zwischen metall
8、ischen Leiterbahnen (IEC 62374-1:2010) This European Standard was approved by CENELEC on 2010-11-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration
9、. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by transla
10、tion under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Esto
11、nia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. - 2 -Foreword The text of document 47/2063/FDIS, future edition 1
12、of IEC 62374-1, prepared by IEC TC 47, Semiconductor devices, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62374-1 on 2010-11-01. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and CENELEC
13、shall not be held responsible for identifying any or all such patent rights. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2011-08-01 latest date by which the national stand
14、ards conflicting with the EN have to be withdrawn (dow) 2013-11-01 _ Endorsement notice The text of the International Standard IEC 62374-1:2010 was approved by CENELEC as a European Standard without any modification. _ BS EN 62374-1:2010EN 62374-1:2010 (E)3 CONTENTS 1 Scope. .5 2 Terms and definitio
15、ns . 5 3 Test equipment. .6 4 Test samples 6 4.1 General .6 4.2 Test structure .6 5 Procedures. 8 5.1 General .8 5.2 Pre-test .8 5.3 Test conditions . .8 5.3.1 General . 8 5.3.2 Electric field . 8 5.3.3 Temperature. 9 5.4 Failure criterion . 9 6 Lifetime estimation 10 6.1 General .10 6.2 Acceleratio
16、n model10 6.3 Formula of E model . .10 6.4 A procedure for lifetime estimation .10 7 Lifetime dependence on inter-metal layer area 13 8 Summary. .13 Annex A (informative) Engineering supplementation for lifetime estimation . . 14 Bibliography.16 Figure 1 Schematic image of test structure (comb and s
17、erpent pattern) . .7 Figure 2 Schematic image of test structure (comb and comb pattern) 7 Figure 3 Cross-sectional image of test structure for line to stacked line including via 8 Figure 4 Cross-sectional image of test structure for stacked line to stacked line including via 8 Figure 5 Test flow dia
18、gram of constant voltage stress method . .9 Figure 6 Weibull distribution plot .11 Figure 7 Procedure to estimate the acceleration factor due to the electric field dependence .12 Figure 8 Procedure to estimate the activation energy using an Arrhenius plot 12 BS EN 62374-1:2010EN 62374-1:2010 (E) 4 S
19、EMICONDUCTOR DEVICES Part 1: Time-dependent dielectric breakdown (TDDB) test for inter-metal layers 1 Scope This part of IEC 62374 describes a test method, test structure and lifetime estimation method of the time-dependent dielectric breakdown (TDDB) test for inter-metal layers applied in semicondu
20、ctor devices. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 leakage current of inter-metal layer Ileakcurrent through the dielectric layer when a use voltage is applied 2.2 initial leakage current of inter-metal layer Ileak-0leakage current
21、 of inter-metal layer before a stress voltage is applied 2.3 compliance current Icomp maximum current of the voltage-forcing equipment NOTE A compliance limit can be specified for a particular test. 2.4 measured leakage current of inter-metal layer Imeas measured current in constant voltage stress (
22、CVS) test 2.5 breakdown time tbdsummation of time during which stress voltage is applied to inter-metal layer until failure NOTE In CVS test, applied stress voltage is interrupted by measuring and assessing repeatedly (see Figure 5). 2.6 dielectric layer thickness td physical thickness of dielectric
23、 layer which is pitched between metal lines 2.7 stress voltage Vstressvoltage applied during CVS test BS EN 62374-1:2010EN 62374-1:2010 (E) 5 2.8 use voltage Vuse voltage applied during pre-test and used for lifetime estimation NOTE This voltage is usually power supply voltage. 2.9 metal electrode l
24、ength L total length of metal electrode which is pitching the dielectric layer 2.10 electric field for inter-metal layer Eimvoltage across a dielectric layer divided by its horizontal width between metal lines NOTE The dielectric layer width should be determined by a consistent documented method by
25、the physical measurement method with SEM, TEM or other. The method or a reference to a documented standard which describes the method should be included in the data report. 3 Test equipment This TDDB test can be applied by both the package level test and the wafer level test. A high temperature oven
26、 is used for the package level test. In the case of the wafer level test, a wafer probe with a hot plate or hot chuck is necessary. Additionally the instruments need to have sufficient resolution to detect changes of leakage current under high temperature condition. NOTE Package level test is test o
27、n test structures assembled in package. 4 Test samples 4.1 General Test samples for TDDB test for inter-metal layer shall have the following test structure. 4.2 Test structure An appropriate test structure for this test is an interdigitated one as shown in Figure 1, consisting of comb and serpent pa
28、tterns, which are connected to the voltage source lines. There is an alternative structure, that is the interdigitated comb and comb structure shown in Figure 2. Test structure leads shall be designed to prevent unexpected failures outside the test structure during the TDDB test. Patterns with vias
29、(Figures 3 and 4) need to be considered because the failure mechanism might be different from a line-to-line pattern without via. Unless otherwise specified comb and serpent pattern are be recommended. The minimum line-to-line spacing is the most severe condition for this mechanism. Therefore, the m
30、inimum dimension allowed by the layout rule shall be evaluated. The total length of the metal line is recommended to be in the range from 0,01 m to 1 m. For the accurate lifetime estimation, it is recommended that at least three device conditions of area or length be used, so proper scaling can be a
31、chieved. Unless otherwise specified the above-mentioned conditions shall be used for test structure parameters. BS EN 62374-1:2010EN 62374-1:2010 (E) 6 Width of dielectric layer Metal line (serpent pattern) Metal line (comb pattern) Dielectric layer between metal lines V V GND Metal line (comb patte
32、rn) IEC 2106/10 Figure 1 Schematic image of test structure (comb and serpent pattern) Metal line (comb pattern) Dielectric layerWidth of dielectric layer V GND Metal line (comb pattern) IEC 2107/10 Figure 2 Schematic image of test structure (comb and comb pattern) BS EN 62374-1:2010EN 62374-1:2010 (
33、E) 7 Upper layer metal Via Lower layer metal Inter-metal layer Barrier layer IEC 2108/10 Figure 3 Cross-sectional image of test structure for line to stacked line including via Upper layer metal Via Lower layer metal Inter-metal layer Barrier layer IEC 2109/10 Figure 4 Cross-sectional image of test
34、structure for stacked line to stacked line including via 5 Procedures 5.1 General In this section the test procedure is explained. Figure 5 shows a procedure for the constant voltage stress method. 5.2 Pre-test Pre-test is performed to identify initial failed samples. The leakage current is measured
35、 at the applied use voltage. If the measured current is larger than the defined criterion, then that sample is rejected as an initial failed sample. When obtaining the defective distribution as necessary, the CVS test without pre-test may be effective. In this case the pre-test can be omitted. 5.3 T
36、est conditions 5.3.1 General The following test condition is recommended for the TDDB test. The sample size should be selected to provide the necessary confidence level for the application. 5.3.2 Electric field Vstressshall be decided by a trial test to get the TDDB lifetime data in a reasonable tim
37、e. It is preferable to select at least three electric fields for estimating the field acceleration factor. BS EN 62374-1:2010EN 62374-1:2010 (E) 8 5.3.3 Temperature It is preferable to select at least three temperatures. Use-junction temperature shall be in the test temperature range for estimating
38、the temperature acceleration factor (activation energy). 5.4 Failure criterion Unless otherwise specified, Imeaswhich exceeds the failure criterion indicates device failure. The measurement condition (temperature, electric field) for the pass judgment shall be set up at use conditions or stress cond
39、itions. The leakage current shift for failure shall be established in consideration of the initial current, the measurement resolution, and the products specifications. Apply operating useconditionsleakage current measurementI leak-0 E2 E3”. t1, t2, t3 (h) breakdown time when the cumulative failure
40、reaches A1 % Figure 6 Weibull distribution plot BS EN 62374-1:2010EN 62374-1:2010 (E) 11 Electric field E (MV/cm) Ln Lifetime E dependence plot E1 E3 E2 t1 t3 t2 TuseEuseSlope: IEC 2112/10 Figure 7 Procedure to estimate the acceleration factor due to the electric field dependence Ln LifetimeArrheniu
41、s plotT1 T2T3t1 t2t3Slope : Ea1/T (1/K)IEC 2112/10 Figure 8 Procedure to estimate the activation energy using an Arrhenius plot BS EN 62374-1:2010EN 62374-1:2010 (E) 12 7 Lifetime dependence on inter-metal layer area Revised lifetime is often used to carry out lifetime estimation of actual products
42、with various dielectric areas which is pitched between metal lines. To convert the test sample lifetime with a certain dielectric area into an actual product lifetime with a different one, the following formula shows a simple and easy procedure, which uses a Weibull distribution parameter. The formu
43、las (2) and (3) show a simple Weibull, so only Weibull is recommended as the distribution of choice. In general, the line-to-line spacing of the test structure is constant. Therefore, the metal electrode length L which is the pitching dielectric layer can be used as the dimension parameter instead o
44、f the dielectric area A of formula (3). mAATTFTTF12112= (2) mLLTTFTTF12112= (3) where TTF1, A1and L1is the time to failure, its dielectric area which is pitched between metal lines and its length of metal electrode of test sample, respectively; TTF2, A2and L2is the time to failure, its dielectric ar
45、ea which is pitched between metal lines and its length of metal electrode of actual product, respectively; m is the shape parameter of Weibull distribution NOTE Sufficient consideration should be taken to avoid high electric fields in the corners of the test structure. If voltage stress concentratio
46、n in the corners occurs due to improper test structure design, the failure distribution will deviate from the intrinsic failure distribution. Failure analysis should be done to confirm that failure has occurred in the corner of the metal line. In case that the extrinsic failures concentrate on the c
47、orner, they may be excluded from the lifetime analysis. 8 Summary The following details shall be specified in the applicable specification: a) stress conditions (voltage and temperature); b) conditions of device for failure criteria (leakage current and its measurement condition); c) specific patter
48、n and its dimension of test structure; d) sample and lot size for testing; e) specific lifetime estimate model; f) specific lifetime estimate condition. BS EN 62374-1:2010EN 62374-1:2010 (E) 13 Annex A (informative) Engineering supplementation for lifetime estimation A.1 Typical value of acceleratio
49、n factor The basic formula of E model is the same as shown in 6.3. Typical acceleration factors are indicated below. According to the result of recent research, various types of combination which consisted of both a material and inter-metal layer structure brought widely varied values. The test method of Subclause 5.3 is recommended to extract the appropriate acceleration factors for lifetime estimation. ()EkTEATTF expexpa= (A.1) is the electri
