{"title":"Limiting oxide failure mode versus oxide thickness. Some insights for deep-submicron technologies","authors":"S. Bruyère, E. Vincent, G. Ghibaudo","doi":"10.1109/IRWS.1999.830563","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830563","url":null,"abstract":"This paper focuses on the different aspects related to the gate oxide reliability for oxide thicknesses ranging between 7 and 2.5 nm in order to get some insights on the failure modes which will dominantly limit the future technologies' dielectric reliability. First, the SILC bell-shaped behavior with the oxide thickness presages that the SILC will not be a dielectric reliability limitation for the future CMOS technologies. Second, the impact of the larger spread of the intrinsic breakdown distribution on the oxide lifetime is underlined. Third, the quasi-breakdown occurrence is characterized and a methodology is proposed in order to statistically analyze quasi-breakdown phenomenon. Finally, the question of the oxide limiting failure mode is developed: for oxide thicknesses ranging between 5 and 3 nm, quasi-breakdown phenomenon appears to be the most limiting failure mode; on the contrary, for 2.5 nm oxide and probably thinner, the breakdown event occurs before the quasi-breakdown one at nominal conditions.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122795183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temperature gradient effects in electromigration using an extended transition probability model and temperature gradient free tests. I. Transition probability model","authors":"K. Jonggook, V. Tyree, C. R. Crowell","doi":"10.1109/IRWS.1999.830555","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830555","url":null,"abstract":"Temperature gradient effects incorporated in electromigration are examined via the movement of vacancies. To explain the movement of metal ions or vacancies, an extended transition probability model with temperature gradients and vacancy concentration gradients is compared with the usual drift-diffusion model including the equation of continuity and the Einstein relationship. The self-consistent constant vacancy source boundary condition for repeated SWEAT structure is proposed so as to solve the equation of continuity. A derived time-to-fail equation from our model with temperature gradients is similar to the original Black's equation. Also temperature gradient effects are simulated using our temperature model and the vacancy concentration profile that will ultimately lead to failure is investigated for various current densities and substrate temperatures. Based on our simulation and experiments at extremely high current density (typical of SWEAT type tests), there is a failure site with very small standard deviation for both NIST and SWEAT when strongly controlled by temperature gradient effects. By adding a compensating heat flow structure under the interconnection region, a temperature gradient free test structure was designed and tested with various temperature gradients. Test results show dramatic changes in failure location and time to failure as the amount of the temperature gradient is varied.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115242838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temperature dependence of resistance in Black's equation and in calibration for SWEAT and NIST structures: the parameter T/sub EO/","authors":"C. R. Crowell, C. Shih, K. Jonggook, V. Tyree","doi":"10.1109/IRWS.1999.830579","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830579","url":null,"abstract":"The equation for resistance R(T) at temperature T can be expressed in the form R(T)=(dR/dT).(T-T/sub EO/. When dR/dT is constant over the range of your experiment, T/sub EO/ is then a constant, the temperature at which R(T) extrapolates to zero. If we wish to express the corresponding relationship with /spl beta/(T/sub r/), the temperature coefficient of resistivity (TCR) at temperature T/sub r/, /spl beta/(T/sub r/) is defined in the form /spl beta/(T/sub r/)=(dR/dT/sub r/).(1/R(T/sub r/))=1/(T/sub r/-T/sub EO/). For both these equations it is desirable to use the Kelvin scale for T, especially when activation energy terms occur in the test under consideration. Our experimental measurements of temperature calibration have yielded T/sub EO/ values less than 40 degrees Kelvin, and with sufficient accuracy such that materials properties can be usefully determined provided that the test temperature is not too high. When /spl beta/(T/sub r/) is specified by an independent source, it is necessary that T/sub r/ be included in both theoretical and experimental cases.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124503680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Product reliability and maximum voltage limits from extrinsic gate oxide voltage ramp data","authors":"R. Hijab","doi":"10.1109/IRWS.1999.830566","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830566","url":null,"abstract":"The failure rate methodology applied previously to TDDB constant voltage data is extended to VRAMP data, to obtain the failure rate for a given supply voltage and gate oxide area or conversely, the maximum supply voltage for a given failure rate. The maximum voltage limit for sub-circuits occupying a small fraction of the chip area can also be determined. The methodology relies on the effective-oxide-thickness model and the unified TDDB model, where the E-model dominates at low fields and the 1/E-model dominates at high field.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134069637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Okandan, S. Fonash, B. Maiti, H. Tseng, P. Tobin
{"title":"Analysis of evolution to and beyond quasi-breakdown in ultra-thin oxide and oxynitride","authors":"M. Okandan, S. Fonash, B. Maiti, H. Tseng, P. Tobin","doi":"10.1109/IRWS.1999.830569","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830569","url":null,"abstract":"The wearout and eventual failure of ultra-thin dielectrics have been of great interest since these dielectrics are critical in the reliability and performance of the state of the art CMOS technologies. This paper presents detailed analysis of transistors with 30 /spl Aring/ (measured by ellipsometry) oxide and oxynitride dielectrics as they evolve to and beyond quasi-breakdown due to FN stresses. Subsequent anneals and stresses were also performed to simulate the effects of further processing.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116265377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Menon, J. Fazekas, J. von Hagen, L. Head, C. Ellenwood, H. Schafft
{"title":"Impact of test-structure design and test methods for electromigration testing","authors":"S. Menon, J. Fazekas, J. von Hagen, L. Head, C. Ellenwood, H. Schafft","doi":"10.1109/IRWS.1999.830557","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830557","url":null,"abstract":"The ultimate goal of this work is to develop design guidelines for electromigration test structures and to revise existing standard test methods for fast wafer-level and conventional package-level stress testing. These tests all involve stressing a sample of test structures and measuring their failure times to obtain sample estimates of the median-time-to-failure, t/sub 50/, and the standard deviation of the log/sub e/ of the failure times, or sigma(/spl sigma/). Four test methods (Standard Wafer Level Electromigration Accelerated Test (SWEAT), IsoI-SWEAT, Isothermal, and ASTM) and six test structures (four SWEAT-type and two ASTM-type) were used to stress Al-1% Si metallization (1 /spl mu/m and 3 /spl mu/m) lines. It was observed that /spl sigma/ is not affected by test structure design, but is affected by the test method. /spl sigma/(SWEAT) was the largest and /spl sigma/(IsoI-SWEAT) was the smallest, quite understandable based on how the stress in the test methods differ. Sigma was also larger for narrower lines. The manner of terminating the test line in the ASTM-type structures did not impact lifetime, except in the narrowest lines, where the lifetime was higher for the structures with split end segments (contrary to expectations). An opening in the passivation over the heat sinks in the SWEAT-type structures did not impact lifetime. A thermal analysis showed that the usual technique of using the fractional change in resistance of the test structure to estimate the joule heating of test lines can lead to underestimates of the stress temperature. The larger the relative resistance of the heat sinks of the test structure, the greater the stress temperature of the test line will be under estimated and the lower the t/sub 50/ will be. The analysis also helped explain the observed differences in the t/sub 50/ values for the different test structures.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114807013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the bimodal lognormal distribution of electromigration lifetimes","authors":"M. Lepper, A. Fischer, A. Zitzelsberger","doi":"10.1109/IRWS.1999.830581","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830581","url":null,"abstract":"The accurate prediction of electromigration-limited lifetime based on high current density and temperature stressing is one of the key issues in reliability methodology. Especially the choice of the underlying distribution model is of importance since extrapolated life times for operation conditions depend on it. Two sets of electromigration lifetime data gathered from submicron via-line structures an presented which do not show log-normal failure behaviour. They can be fitted assuming a bimodal lognormal distribution. The intention of this paper is to characterize different bimodal lognormal distributions, to review some statistical basics and to give a proposal to handle bimodal failure distributions for lifetime projection.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128304980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reliability aspects of stress-induced voiding in 0.25 /spl mu/m metallization","authors":"A. Zitzelsberger, M. Lehr","doi":"10.1109/IRWS.1999.830552","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830552","url":null,"abstract":"Stress Void formation of Al based interconnects (0.25 /spl mu/m ground rule) due to high density plasma (HDP) oxide deposition process has been reported in the literature very recently. The voids are caused by the thermal expansion mismatch between Al and oxide. It is proposed that the voiding is accelerated by the TiAl/sub 3/ formation. In this paper, void formation is investigated for differently processed metal lines. Measurements include stress-migration (SM) as well as electromigration (EM) reliability tests on two types of test structures. The aim of the work was to study the influence of the stress voids on the EM performance. From reliability investigations presented in this paper it can be concluded that pre-existing voids in metal lines result only in a small decrease of electromigration median time to failure (MTF). However a decrease of the current density exponent n is found. This leads to a reduction in life time.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130229443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An evaluation of electrical linewidth determination using cross-bridge and multi-bridge test structures","authors":"L. Head, H. Schafft","doi":"10.1109/IRWS.1999.830556","DOIUrl":"https://doi.org/10.1109/IRWS.1999.830556","url":null,"abstract":"The multi-bridge method is often used in the industry to measure electrical linewidths of interconnect lines because it requires less sensitive equipment than the standard cross-bridge method. The method assumes that the linewidth process bias is independent of design width, which is shown here to be only approximately correct. This can result in linewidth determinations that are significantly different from the values obtained by the cross-bridge method. This is observed most often at the narrower designed widths. A composite method is described that minimizes these differences. The multi-bridge test structure can also be used to detect the linewidths at which chemical mechanical polishing (CMP) induces \"dishing\" effects in copper lines.","PeriodicalId":131342,"journal":{"name":"1999 IEEE International Integrated Reliability Workshop Final Report (Cat. No. 99TH8460)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121942096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}