High Temperature Oxidized SnO 2

Undoped and Sb-doped tin oxide films were prepared by d.c. reactive ion sputtering in an argon atmosphere with oxygen partial pressures ranging from 0 to 50%. The films were anneled in oxygen in the temperature range 360 - 893℃. The effect of thermal annealing on the changes in electrical and structural properties is described

Defects in high temperature and high pressure processed Si:N revealed by deuterium plasma treatment

Deuterium is accumulated by defects in nitrogen-implanted silicon (Si:N). This effect is investigated for Si:N processed at HT ≤ 1400 K, also under enhanced hydrostatic pressure, HP ≤ 1.1 GPa. Si:N was prepared from Czochralski grown silicon by N₂⁺ implantation at E = 140 keV with nitrogen doses, DN = 1–1.8•10¹⁸ cm⁻². Si:N was subsequently processed in RF deuterium plasma to prepare Si:N,D. Si:N and Si:N,D were investigated by Transmission Electron Microscopy (TEM), X-ray and Secondary Ion Mass Spec- trometry (SIMS) methods, also after additional annealing at 723 K. In heavily implanted Si:N (DN = 1.8•1010¹⁸ cm⁻²), plasma treatment leads to deuterium pile up to сD1 = 2•10²¹ cm⁻³ at a depth, d = 50 nm, while, at d = 80–250 nm, deuterium concentration is practically constant with сD2 = 1•10²¹ cm⁻³. This suggests dominating accumulation of deuterium within the bubble-containing areas. Determination of deuterium depth profiles in Si:N,D can reveal implantation- and processing-induced defects.В работе рассмотрены эффекты влияния обработки температурным отжигом (до 1400 K) и гидростатическим давлением (до 1.1 GPa) на дефектный состав SOI-структур (silicon-on-insulator) на основе образцов Si:N – материала, широко используемого в полупроводниковых технологиях. Были получены новые данные, свидетельствующие об образовании скрытых дефектосодержащих слоев в образцах кремния, имплантированного азотом, и подвергнутых обработке высокими температурами и давлениями. Такие структуры становятся центрами абсорбции дейтерия из плазмы – его накопление и распределение внутри образца зависят от микроструктуры материала. Таким образом, показано, что обработка в дейтериевой плазме с дальнейшим определением концентрационных профилей по глубине образца может быть полезной для оценки микроструктурыУ роботі розглянуто ефекти впливу обробки температурним відпалом (до 1400 K) і гідростатичним тиском (до 1.1 GPa) на дефектний склад SOI-структур (silicon-oninsulator) на основі зразків Si:N – матеріалу, широко використовуваного в напівпровідникових технологіях. Було отримано нові дані, що свідчать про утворення прихованих дефектовміщуючих шарів в зразках кремнію, імплантованого азотом, підданих обробці високими температурами та тиском. Такі структури стають центрами абсорбції дейтерію з плазми – його накопичення і розподіл усередині зразка залежать від мікроструктури матеріалу. Таким чином, показано, що обробка в дейтерієвій плазмі з подальшим визначенням концентраційних профілів по глибині зразка може бути корисною для оцінки мікроструктури Si:N-зразка, особливо зважаючи на потенційну застосовність в SOI-технологіях

Pressure-induced transformations during annealing of silicon implanted with oxygen

Enhanced hydrostatic pressure (HP, up to 1.5 GPa) applied during annealing at up to 1570 K (HT) of silicon with oxygen introduced by implantation (Si:O), exerts pronounced effect on the transformation of oxygen admixture. In particular, HP affects the microstructure of Si:O and a creation of oxygen-enriched (for implanted oxygen dose, D ≤ 1·10¹⁷ cm⁻²) or continuous (for D ≥ 6·10¹⁷ cm⁻²) buried SiO2 layers. Numerous treatment parameters contribute to the HP-induced phenomena in processed Si:O, among these are the HPaffected mobility and solubility of implanted oxygen as well as of silicon interstitials and of other implantation-induced defects and so the stability of oxygen clusters/precipitates; the misfit at the SiO₂/Si boundary is tuned by HP

Defects in silicon heat-treated under uniform stress and irradiated with fast neutrons

Silicon samples of initial oxygen concentration [O 17 cm -3 were subjected to various high temperature-high pressure (HT-HP) treatments in the temperature range 900-1050 °C. Afterwards, the samples were irradiated by fast neutrons and then isothermally annealed at 400 °C. Infrared spectroscopy, X-ray diffraction, transmission electron microscopy (TEM), optical spectroscopy and selective etching measurements were performed. Besides the precipitates and the dislocation loops that usually form, small defect clusters were also detected in the samples. The presence of these clusters is revealed due to their decoration with radiation induced point defects, and attributed to the HP treatment

Strain state in Mn-implanted silicon annealed at high temperature

In this work an influence of thermal annealing of Mn-implanted silicon on strain state of silicon matrix is presented. During post-implantation annealing, nanocrystalline tetragonal Mn4Si7 compound is formed. A strong correlation between the size of nanoinclusions and the matrix strain state is detected

Defect structure of Czochralski silicon co-implanted with helium and hydrogen and treated at high temperature - pressure

Effect of stress created by Ar hydrostatic pressure (HP) up to 1.1 GPa during annealing at the high temperature (HT) 1070 K (HT-HP treatment) on microstructure of Czochralski grown silicon co-implanted with helium and hydrogen Si:(He,H) using the same doses of He+ and H₂+ (DH,He= 5·10¹⁶ cm⁻², at energy 50 and 150 keV, respectively) was investigated by means of X-ray (synchrotron) diffraction, transmission electron microscopy, and electrical measurements. The nanostructured sponge-like buried layers are formed in Si:(He,H) by annealing / high pressure treatment. Decreased interference, diffuse scattering and individual contrast are observed in the synchrotron topograms for HT-HP treated Si:(He,H). The treatment at 723 K and HP results in an additional donor formation as a sequence of the implantation-disturbed layer. The HP-mediated (retarded) out-diffusion of hydrogen and helium is in part responsible for the effects observed

Pressure-induced structural transformations in Si:V and Si:V, Mn

Semiconductors doped with magnetically active atoms are expected to find application in spintronics. Si samples implanted with Mn⁺ (Si:Mn) or with V⁺ (Si:V) can order magnetically after processing at high temperature (HT) and also under enhanced hydrostatic pressure (HP). This work presents new results on structure-related properties of single crystalline Si implanted at 200 keV with V⁺ as well as that co-implanted additionally with Mn⁺ ions (Si:V, Mn), with dosages DV⁺ ≤ 5·10¹⁵ cm⁻² and DMn⁺ = 1·10¹⁵ cm⁻². The samples were processed for 1–5 h at HT ≤ 1270 K under HP ≤ 1.1 GPa. Secondary Ion Mass Spectrometry, Transmission Electron Microscopy, X-ray and related methods were applied for sample characterization. The HT- (HP) treatment affects, among others, solid phase epitaxial re-growth (SPER) of amorphous silicon created at implantation and distribution of implanted species

Hydrogen gettering in annealed oxygen-implanted silicon

Hydrogen gettering by buried layers formed in oxygen-implanted silicon (Si:O prepared by O²⁺ implantation at the energy 200 keV and doses 10¹⁴ and 10¹⁷ cm⁻²) was investigated after annealing of Si:O at temperatures up to 1570 K, including also processing under enhanced hydrostatic pressure, up to 1.2 GPa. Depending on processing conditions, buried layers containing SiO₂₋x clusters and/or precipitates were formed. To produce hydrogen-rich Si:O,H structures, Si:O samples were subsequently treated in RF hydrogen plasma. As determined using secondary ion mass spectrometry, hydrogen was accumulated in sub-surface region as well as within implantation-disturbed areas. It has been found that hydrogen was still present in Si:O,H structures formed by oxygen implantation with the dose D = 10⁷ cm⁻² even after post-implantation annealing up to 873 K. It is concluded that hydrogen accumulation within the disturbed areas in Si:O as well as in SOI structures can be used for recognition of defects

СОПРЯЖЕННЫЕ ФУКЦИИ НА ОТРЕЗКЕ И СООТНОШЕНИЯ ДЛЯ ИХ НАИЛУЧШИХ РАВНОМЕРНЫХ ПОЛИНОМИАЛЬНЫХ ПРИБЛИЖЕНИЙ

A relation between the best polynomial approximations of the function assigned on a segment and the function conjugated to it is found. In the periodic case, a similar relation is obtained by S. B. Stechkin. The inequality of G. Szegö type is also proved for the derivatives of an algebraic polynomial.В работе найдено соотношение между наилучшими равномерными полиномиальными приближениями функции, заданной на отрезке, и ее сопряженной, аналогичное соотношение в периодическом случае было получено С. Б. Стечкиным. Также доказано неравенство типа Сегё для производных алгебраического многочлена.