P2-473Study of hydrogen detection and deuterium diffusion in materials by means of SIMSKey Words: Hydrogen, solubility, diffusion, SIMSHydrogen in the devices affects performance and reliability, requiring in-situ detection. Dynamic-SIMS is an effective analytical method for this problem. Recently, the effect of hydrogen under applied electric fields on the reliability of MLCCs has been elucidated. It is expected that research on the relationship between device reliability and hydrogen will progress in the future. ⚫Methods for evaluating the reliability of 1H signals were presented.⚫SIMS showed 1H background of 1.2x1017/cm3.⚫Zn image revealed mechanism of SnO2densification. ⚫Diffusion and pathways of 2H in SnO2were clarified. ConclusionSIMSisaninstrumentcapableofin-situanalysisofhydrogen(1H)indevices.Toachievethis,thekeyistoreduce1Hbackgroundandacquire1Hsignalfromthematerials.I.Adsorptionof1Hfromvacuum,II.Edgeeffectofsurface,III.1Hdiffusiontowardsirradiationarea,IV.Unintentional1Hsignal.Detection of 1H signals in materialsDiffusion experiments using deuterium⚫Study on detection limit reduction.⚫Exploration of hydrogen ion materials using deuterium.Future PlanTin dioxide (SnO2) is used as a gas sensor device. While water vapor (H2O) is known to cause performance degradation during use. The relationship between this issue and 1H in device remains unclear. To address this problem, we studied on deuterium (2H) behavior in dense SnO2ceramics. IntroductionWe have carried out the research on hydrogen behavior in oxides using SIMS. While in-situ analysis of 1H is required for oxide devices, utilizing 2H is effective for model experiment. Now, to utilize SIMS for hydrogen ion materials exploration, we are considering the use of cryogenic system, exploring new preparation methods for analysis, and SIMS modification. Theme underDiscussionHydrogen ion materials group, GREEN Isao SAKAGUCHIE-mail：：SAKAGUCHI.Isao@nims.go.jp100mOut-side of irradiationIn-side of irradiation Beam edgeEdge effectAdsorption of 1H inblack areaSurface diffusionFig. 1. 1H image byprimary illumination. Zn 0.25mol%8x10-12cm2/sZn 2.0mol%7x10-13cm2/s200 ºC, 2hDepth / m051010151019101610171018C[2H] /cm3O2-DO-Zn 0.25 mol%1.4 eVZn 2.0 mol%1.2 eVD / cm2/sReciprocal temperature / 103/K2.22.01.81.61.410-1310-1210-1110-1010-9400300250200Fig. 2. Results of crater shape (a) and analytical results (b).Sample is 1H doped oxide ceramics. Crater bottom is flat. Fig. 3. Results of crater shape (illustration) and analytical results.(a)is ion intensity vs. time. (b) is concentration vs. time.Current analysis shows 1H background of 1.2x1017/cm3. Below,weshowmethodstodetectthereal1Hsignals.Primaryilluminationmethod.Raterreductionusinggaussianbeam.Increase of beam current enhances secondary ion signal. 1H concentration is to be 4.5x1018/cm3. (a)(b)Depth (m)Current ()Intensity (cps)Fig. 4. Zn distribution in dense SnO2and line analysis.Fig. 5. 2H concentration profiles in dense SnO2.Fig. 6. High-resolution ion images in dense SnO2.2H diffuses in SnO2grains. Fig. 7. Temperature dependence of 2H diffusion.Preparation of dense SnO2ceramicsZnO: 0.25 –2.0 mol.%Sintering condition: 1280 –1440 , 4h in airDisk density after sintering: 6.8 –6.9 g/cm3Densification mechanism during sintering:Zn segregation is an evident of Zn2SnO4formation. This suppressed decomposition ofSnO2, as a results dense SnO2was obtained.Deuterium (2H) diffusion in dense SnO2ceramics. Figure 1 shows some factors of 1H background.ResultsFrom Fig. 5, 2H concentration profiles decreased simply. This suggested the simple diffusion mechanism. Increase of ZnO in SnO2limited 2H concentration.From, Fig. 6, 2H diffused in SnO2grains.From, Fig. 7, 2H diffusion in SnO2showed the activation energy in the range of 1.2 –1.4 eV.
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