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

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

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

The effect of high pressure - High temperature treatment on neutron irradiation induced defects in Czochralski silicon

Czochralski-grown (Cz-grown) silicon crystals of the same initial oxygen content (8.33×1017 cm-3) were subjected to various high temperature - high pressure (HTHP) treatments for different time durations. Subsequently, the crystals were irradiated by fast neutrons at ∼50°C. One of the main defects form is VO pair (A-Center) usually identified in the Infrared (IR) Spectra by the 830cm-1 Localized Vibrational Mode (LVM) band. Upon annealing, this defect is converted to the VO2 defect responsible for a LVM band at 887cm-1. The purpose of this work is to study the effect of various combinations of HTHP treatment prior to irradiation on the annealing behaviour of the VO defect and particularly on its conversion to the VO2 defect. We have concluded that the conversion of VO to VO2 depends on the forms of oxygen impurity (i.e. oxygen aggregates, precipitates etc.) and on other defects created in the sample after the HTHP treatment, as for example dislocations and stacking faults. © 2001 SPIE