Positron trap sites in the native oxide film grown on a hydrogen-terminated silicon surface

Fujinami, Masanori; Chilton, Neil B.

doi:10.1063/1.110119

Cited by 7 publications

(4 citation statements)

References 18 publications

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“…Although Gusev et al reported that no interface oxide was present between H-terminated Si and Al 2 O 3 , 20 Fujinami et al reported that rinsing in pure water for 30 min or more after HF treatment initiated oxidation of the Si surface even at room temperature. 21 In this study, isopropyl alcohol ͑IPA͒ was used instead of H 2 O in Al 2 O 3 ALD in order to prevent the interface oxide from being formed during the film deposition. Moreover, the use of IPA avoids problems caused by the condensation of H 2 O vapor onto the reactor wall and gas delivery line, which would generate particles and elongate the pulse time of inert gas to purge out H 2 O vapor from the reactor.…”

mentioning

confidence: 99%

Atomic Layer Deposition of Al[sub 2]O[sub 3] Thin Films Using Trimethylaluminum and Isopropyl Alcohol

Jeon

Yang²,

Lee³

et al. 2002

J. Electrochem. Soc.

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Al 2 O 3 thin films were deposited on Si substrates by atomic layer deposition ͑ALD͒ using Al(CH 3 ) 3 ͑trimethylaluminum, TMA͒ as a metal source and (CH 3 ) 2 CHOH ͑isopropyl alcohol, IPA͒ as an oxygen source at 250°C. The film growth rate is saturated at 0.8 Å/cycle, and it is slightly lower than that for the procedure which uses water vapor instead of IPA. The as-deposited film has a stoichiometry close to Al 2 O 3 ͑Al/O ratio ϳ2:3.1͒ and the residual carbon content of the films is below the detection limit of secondary ion mass spectroscopy. An interface oxide between the Al 2 O 3 film and Si-substrate was not detectable on the asdeposited film by transmission electron microscopy. However, after annealing at 800°C for 5 min, an interface oxide is newly formed even under the neutral ambient of Ar, and it grows thicker under the oxidizing ambient of O 2 . That is, oxygen, which is needed for forming the interface oxide during the annealing process is supplied from both of the ambient oxygen and the excess oxygen in the films. Thus, although the loss of dielectric constant is inevitable during the annealing process, it can be minimized by using IPA in Al 2 O 3 ALD.As the size of microelectronic devices is scaled down, oxide films with high dielectric constants are required for gate and capacitor dielectrics. Even though SiO 2 is an excellent dielectric material in many features, the preparation of reliable SiO 2 films thinner than 30 Å is difficult, because of the quantum mechanical tunneling of electrons, which generates a large leakage current across the films. 1 Thus, an alternative oxide film with higher dielectric constant than SiO 2 is needed. 2 In this respect, Al 2 O 3 has been considered as a possible candidate for gate oxides as well as Ta 2 O 5 , HfO 2 , and ZrO 2 . 3-5 Also, Al 2 O 3 is considered as a promising capacitor dielectric, which can replace silicon oxynitride ͑SiON͒ in future dynamic random access memories ͑DRAM͒. 6 In addition, Al 2 O 3 has been recently regarded as a good passivation layer, which can prevent hydrogen penetration into the active region of semiconductor devices. 7 In preparing high-dielectric metal oxides with a thickness in the subhundred angstrom range, atomic layer deposition ͑ALD͒ attracts considerable interest owing to its inherent merits in thin film depositions, such as a digital controllability of film thickness on an atomic scale, a superior conformal deposition on three-dimensional structures, and no particle generation, etc. 8-10 In typical ALD of metal oxide thin films, H 2 O has been most widely used as the oxygen source. [11][12][13][14][15][16] However, by using H 2 O an unwanted interface oxide may be formed between the metal oxides and Si substrates, and it is thought that the interface oxide is composed mainly of SiO x , as the result of the reaction between H 2 O and the Si substrates during the initial stage of the ALD. Hence, the interfusion of the interface oxide would be expected to reduce the dielectric constant of the deposited thin films. 17-19 Th...

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confidence: 99%

Atomic Layer Deposition of Al[sub 2]O[sub 3] Thin Films Using Trimethylaluminum and Isopropyl Alcohol

Jeon

Yang²,

Lee³

et al. 2002

J. Electrochem. Soc.

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“…Note also that the surface S-parameter value (i.e. at E = 0) increases significantly after etching, to close to unity; this is expected to be the case for an H-terminated Si surface [7].…”

Section: Resultsmentioning

confidence: 63%

“…The dopant distribution can be determined experimentally via depth profiling by secondary ion mass 0953-8984/98/4610403+06$19.50 c 1998 IOP Publishing Ltd spectrometry (SIMS) or (in the case of large fluences) Rutherford back-scattering (RBS). PAS offers the ability to profile open-volume defects yielding novel information such as the existence of vacancies to depths beyond-sometimes by a considerable factor-those predicted by TRIM [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the fact that the majority of positrons annihilate in vacancies in the large peak just below the surface means that the ability of PAS to study lower-intensity extended vacancy-type defect tails is limited. The authors therefore combine standard non-destructive PAS with etching of known sample thicknesses, extending the idea of Fujinami and Chilton [7] by controlling the etching process via anodic oxidation.…”

Section: Introductionmentioning

confidence: 99%

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Positron spectroscopy of vacancy-type defects in Si created by 5 keV implantation

Malik

Coleman

Knights

et al. 1998

J. Phys.: Condens. Matter

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Structural damage resulting from the implantation of 5 keV B + ions into FZ-Si has been investigated by positron annihilation spectroscopy (PAS) using a tuneable monoenergetic beam. Four samples, exposed to ion fluences from 2 × 10 12 to 2 × 10 15 cm −2 , were studied. The PAS results demonstrate the applicability of the technique to the study of vacancy-type defects in small-scale device structures created by very low-energy ion implantation. Ion depth profiles determined by SIMS exhibited tails extending well beyond the limit predicted by the code TRIM, attributed to ion channelling. PAS, when extended by repeated measurements after precise etching of 40 and 140 nm of material via anodic oxidation, showed that the vacancy-type defect depth profiles also extended far beyond the limit predicted by TRIM. The ratio of defects to ions increases with depth, suggesting that the defect tails are not simply correlated to the implanted ions but that there may also be a contribution from post-implantation defect diffusion.

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Correlation between the photoluminescence and chemical bonding in porous silicon

et al. 1995

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Positron trap sites in the native oxide film grown on a hydrogen-terminated silicon surface

Cited by 7 publications

References 18 publications

Atomic Layer Deposition of Al[sub 2]O[sub 3] Thin Films Using Trimethylaluminum and Isopropyl Alcohol

Atomic Layer Deposition of Al[sub 2]O[sub 3] Thin Films Using Trimethylaluminum and Isopropyl Alcohol

Positron spectroscopy of vacancy-type defects in Si created by 5 keV implantation

Correlation between the photoluminescence and chemical bonding in porous silicon

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