Толстый интернет-журнал
"Русский переплет"

RUSSIAN PEREPLET
Culture, Science, and Education Portal


Science Space  Culture General Discussion Scientific Discussion Seminars


News: The best of Russian Science and Technology
Under supervision of professor Vladimir M. Lipunov

01.10.2008
17:58

THE DAYS OF SAINT PETERSBURG PHILOSOPHY - 2008

30.06.2008
18:37

Philosophy of Mathematics: Actual Problems

18.06.2007
12:13

MASTER Team Science Release: Discovery of the Black Hole Ergosphere?

24.10.2006
10:50

The International Conference "The International Conference"

29.03.2004
15:54

New domestic processor MCST-R500

09.03.2004
14:00

MASTER is the first russian asteroid factory

25.01.2004
12:51

New Russian "Volga"

17.12.2003
15:00

Russian physicists awarded Nobel Prize

28.11.2003
16:46

Fantastic hetch of Russian physician

11.11.2003
19:33

Aurora on Moscow sky

01.11.2003
11:47

ELEVENTH INTERNATIONAL CONGRESS ON SOUND AND VIBRATION (ICSV11)

16.10.2003
18:58

The first and lonely russian robot-human

06.10.2003
14:40

FRONTIERS OF NONLINEAR PHYSICS

02.10.2003
18:30

MASTER - is the first russian robotic telescope for observations Gamma-Ray Bursts

07.10.2002
14:17

Optical Fiber Sensor at 900 C

10.09.2002
13:24

Inflatable Equipment for Rescue and Descent

24.05.2002
17:16

Isotopically Pure Materials from Russia

    The ISONICS Company began to deliver isotopically pure Silicon-28 to the AMD microprocessor producer. The news did not prove to be absolutely unexpected because ISONICS has been delivering isotopically pure materials for a long time. A year ago there was information concerning delivery of trial isotopically pure silicon for AMD. What turned out to be new, it is the isotope number, Si-28. It allows the thermal conductivity to be increased by fifty per cent. The thermal conductivity is a parameter rather critical in chip production because the most effective heat-sink cooling is needed. Otherwise a chip can be damaged because of localized overheating.

    Why avoiding of dirt admixtures can increase the thermal conductivity to such a great degree? The natural silicon is known to contain about 92 per cent of 28Si isotope. Silicon is a semiconductor, so electronic conductivity does not greatly exceed that of phonons (when heat is transmitted because of atom vibrations in lattice points). The less is the mass of an atom, the greater its moving ability, which leads to increased phonon conductivity. The atoms turn out to vibrate in a strict resonance if a lattice has been constructed from an isotopically pure material. In this case the heat sink is better what results in significant increase in conductivity. The conductivity of 28Si is 40 per cent as high as that of natural silicon at room temperatures, and 60 per cent more at 100C (W.S.Capinski et al. // Appl. Phis. Lett. 1997, v. 71.). ISONICS informs that the maximum value turns out to be near 30K but now one is more interested in room temperatures.

    The price of microprocessors produced with pure 28Si is an order of magnitude as high as that of ordinary costs: 28Si epi wafers - $0.10 to $1.0 28Si bulk wafers - $2 to $25. The cost is not very critical compared with the effectivity because few processors are produced from one wafer.

    The producers are localized in the towns of Sarov, Novoural'sk (Sverdlovsk-44), Seversk (Tomsk-7), Zelenogorsk (Krasnoyarsk-25), and Angarsk. Technology for isotope separation in Russia is considered to be the best in the world. Earlier, however, the whole country was working to meet military requirements and silicon was not supposed to be a material of significance. An approach to control isotopically pure materials has been elaborated in Russia using a laser mass-spectroscopy. The approach allows the main nuclide abundance to be determined within 0.1 per cent, and admixture abundances to be estimated to the accuracy of 6 - 10 per cent.

    Very pure materials are of great effectivity in many high technologies. For example, 114Cd when applied to He - Cd lasers results in their UV output which some times exceeds that of ordinary lasers and increases their durability.

    ZnO is a necessary admixture for a primary reactor contour heat carrier working on boiling water to avoid dangerous radionuclides (58Co and 60Co) washing-out. Using Zn with 64Zn isotope (<1 per cent) suppresses formation of 65Zn, a dangerous radionuclide with a great half-decay period. It is an example of using isotopically depleted materials which allow radiation effects to be reduced significantly.

    58Ni reflects cool neutrons well. When in admixture, it suppresses subsidiary nuclear reactions. 12C and 28Si are of importance for future microelectronics. They have thermal conductivity 50 per cent as high as natural very pure analogues at room temperatures. So their applications appear to decrease chip element sizes significantly and make them as small as 0.18 microns (J. of Atomic Energy Soc. of Jap. 1993, v. 35, N 11). What is nice, conversion to 28Si application does not require any changes in technological process.

    Moreover, in the Institute of Molecular Physics belonging to Kurchatov Institute, 70Ge isotope has been obtained using centrifugal technology of isotope separation. A few hundred grams of this isotope were enriched up to 99.99 per cent. The material was subjected to chemical purification using repeated floating-zone method in Lowrence Berkeley National Laboratory (USA) and Ge-monocrystals were grown up that seemed to be the most perfect synthetic crystals of non-monoisotopic elements.

    Actually almost all materials used in electronic devices may be replaced with their isotopically pure variations. Because of that, devices can appear with absolutely new and unknown (or inaccessible) so far features. The most interesting is the fact that these materials with earlier unattainable properties are now being produced at Russian plants.

    Translated by Nataliya Lipunova

    Review by Kirill Krylov from "Terra & Comp".

16.04.2002
19:31

Hothouse Catastrophe.

12.04.2002
13:23

First Man in Space - 41 Years Ago Sharp!

27.03.2002
22:20

SPACE LIFE in METEORITES?

1|2|3|4|5

 


Email:lipunov@sai.msu.ru

 

Редколлегия | О журнале | Авторам | Архив | Ссылки | Статистика | Дискуссия

Литературные страницы
Современная русская мысль
Навигатор по современной русской литературе "О'ХАЙ!"
Клуб любителей творчества Ф.М. Достоевского
Энциклопедия творчества Андрея Платонова 
Для тех кому за 10: журнал "Электронные пампасы"
Галерея "Новые Передвижники"
Пишите

© 1999 "Русский переплет"
Дизайн - Алексей Комаров

Copyright (c) "Русский переплет"

--------------------------------------------------------------------- Rambler's Top100 Service