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Microcircuits are widely used in technique. Its working elements apply of combination of metals with silicon. Silicids of refractory metals on comparison with other silicids of metals, which are traditionally used, have the row of advantages in plan of electrophysics properties, stableness to action chemically aggressive environments.
Technology of receipt the dicilisids of metals is intensively develops. It involves severe difficulties. Therefore important to study and perfect principles of obtaining of such materials. Works in this direction must be continued, because it is necessary to know conformity to the law of forming of phase composition and structure, which depend from technological parameters processes of receiving.
Initial material for production of microcircuits is a powder alloy from a molybdenum diciliside and tungsten diciliside. The finished product from powder has the form of round "target". For economy of material for production of microcircuits use material which remain after the of was used "target" as the second raw material for making of a new "target". But at sintering such material does not give compression. It negatively influence on properties of the made microcircuits.
The aim of this work in search reasons, which have an influence on appearance of defect at production of microcircuits from a powder alloy on basis of molybdenum disilicide and tungsten disilicide.
For the decision of the put purpose it is necessary to decide the following tasks : research of chemical composition of powder alloy from the molybdenum disilicide and tungsten disilicide, conducting of X-ray structural investigation of initial and processed material, study the technology of making of good by the methods of powder metallurgy.
For making of round "target" powder from a tungsten disilicide and molybdenum disilicide reduce to fine particles by a drum mill, add to the mixture plastificater (poliviniloviy alcohol) and all this mixture press for the obtainingt of the set form. After pressing good subject to sintering. But here the compression of material does not take place. Therefore repeated reduce to fine particles, granulation, pressing and sintering. The prepared target is used for making of microcircuits.
In the process of sputtering microcircuit the most expense of matter of "target" is carried out from its central part and in the center of target appeared perforation. On the picture 1 shown a target until to the use (a) and after of the sputtering of microcircuits (b).
Pic. 1- View target until to the use (a) and after of the sputtering of microcircuits (b).
As shown in the picture 1 in the process of production of microcircuits participates only a 20% initial material. With the purpose of economy of raw material was decided to use material of the worked target in production of new targets. It promoted efficiency of the use of material.
On the first stage the researches of chemical composition of target to the use and after the use were conducted. On standards was conducted the X-ray luorescent analysis by the vacuum device "SPRUT" on the method "Standard with unknown chemical composition". For this purpose were prepared "pills" from boric acid and dispersion powder of alloy by the press of SI 2-1000 with the effort 200kN.
The spectrometer "SPRUT" registers the characteristic lines of elements from Sn (21) to U (92), which lengths of waves lie in a range 0,35 - 3,0 A. In the table 1 the results of researches of chemical composition are reduced.
The table 1 Results of chemical analysis of initial and eventual "targets"
| Percentage, % mass | W | Mo | Si | Cr | Fe | S |
| Initial "targets" | 10,7 | 59,1 | 12,8 | 0,28 | 0,26 | 0,06 |
| Eventual "targets" | 13,5 | 55,5 | 13,4 | 0,35 | 0,33 | 0,08 |
As shown in the table 1 chemical composition of initial and worked "target" differentiates. But this type of analysis is semiquantitative and gives information about the approximate quantity of the contained of elements, the error of this method makes 5-8%.
On the next stage were conducted X-ray structural researches. Initial and worked standards were exposed to the X-ray structural analysis. Was pulled assumption, that at sputtering of tapes with properties unsatisfy to the requirements, was caused by the change of phase composition of powder alloy. Researches were conducted on the x-ray photography devise "DRON-3-3". On the picture 2 the sciagrams of initial and eventual "target" are showed.
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Pic 2- Sciagrams of initial and eventual "target"
As shown in the picture 2 from decoding of sciagrams it appeared, that initial and eventual standard have identical phase composition, alpha and beta of line have the identical value of corner of diffraction. The crystalline grates of tungsten disilicide and molybdenum disilicide are similar between itself and lines on a sciagram are disposed alongside. In other words in the process of sputtering of tapes there is no change of concentration of elements and disintegration of connections on other phases. Distinction is in a presence at the sciagram of initial "target" in the small corners the lines of elements which it was not succeeded to set. There are can be the oxides of metals, which appeared in the process of making of "targets". On the sciagram of the worked "target" these lines are absent because oxides of metals are evaporated at the process of sputtering of microcircuits. As shown in the picture 2 from decoding of sciagrams it appeared, that initial and eventual standard have identical phase composition, alpha and beta of line have the identical value of corner of diffraction. The crystalline grates of tungsten disilicide and molybdenum disilicide are similar between itself and lines on a sciagram are disposed alongside. In other words in the process of sputtering of tapes there is no change of concentration of elements and disintegration of connections on other phases. Distinction is in a presence at the sciagram of initial "target" in the small corners the lines of elements which it was not succeeded to set. There are can be the oxides of metals, which appeared in the process of making of "targets". On the sciagram of the worked "target" these lines are absent because oxides of metals are evaporated at the process of sputtering of microcircuits.So, at the process of sputtering of microcircuits there is no change of chemical and phase composition of "targets" of tungsten disilicide and molybdenum disilicide.
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