Natural sciences

If/I0, 10^8 1 10^6 2 10^4 3 10^2 10^0 ^0^,^20,4 0,6 ^0^,^8^1h, eV
+10 ^^, %  3 ^0^,^6^0^,^81 ^1^,^2^1^,^4^1^,^6^1^,^82 ^В^, Тl -10 -20 ^2 -40 -60 -80 1 -100
1. =0, 2; 2.=1·10^5 R; 3.=5·10^6R Fig. 1 Spectral dependence of samples after radiation dose	1- =0, 2. =1·10^5 R, 3. =5·10^6R Fig.2 Dependence of magnetic resistance of Si samples with nanoclusters on radiation dose, T = 300K, E = 100V/cm

Such samples were loaded into a single pumped ampoule and exposed under the same γ- irradiation conditions. After each irradiation step, the samples were polished to remove the oxide ^{layer SiO}2 ^{and separately examined by room temperature МИК-5 and Hall effect of their electrical} parameters.

а) before irradiation b) 10⁸ R c) 5·10⁸ R d) 10⁹ R

Fig.3 Effect of γ - irradiation on the state of clusters of nickel atoms in silicon

The results of the study showed that in all batches of samples in the radiation dose interval

= 10³  110⁸ R there are practically no significant changes in the state of the clusters, as well as the electrical parameters of the samples, that is, they maintain their initial values. This makes it possible to assume that the parameters of silicon samples with clusters of nickel atoms are sufficiently radiative to the dose of irradiation 10⁸ R. Starting 10⁸ R gradually reduces the size of the clusters, especially in such samples where the clusters have relatively large sizes (3÷5 μm) (Fig. b, c). Note that as clusters decrease in size, their density increases. And at sufficiently high doses of 10⁹ R, the size of the clusters is so reduced that the resolution of the МIК-5 does not allow them to be visually observed (Fig. 3. d).
с


10⁵ ₁₀⁶ 10⁷ 10⁸ 10⁹

Fig.4 Relative change of nickel atom hole concentration in silicon at T = 300 K from radiation dose.

^Np ^{– is the concentration of holes of nickel atoms after irradiation.} 1-lot samples with density of clusters of nickel atoms (23)·10⁷cm^-2 2-lot samples with density of clusters of nickel atoms (35)·10⁶cm^-2 3-lot samples with density of clusters of nickel atoms (57)·10⁵cm^-2

At the same time, the resistivity of samples at doses of 10⁸ R increases and then changes to p-type, that is, there is an inversion of the conductivity sign, and the resistivity of samples that have p-type conductivity decreases, that is, the concentration of holes increases (Fig. 4). These data allow us to conclude that at high doses, due to an increase in the non-equilibrium concentration of vacancies and the breakdown of clusters, individual internode atoms are captured by vacancies and they act as acceptors. As is known, the solubility of nickel in silicon (at 1200^ С) is N5·10¹⁷сm^-3 and the maximum concentration of electroactive atoms N4·10¹⁴сm^-3, this is 0.001% of the total nickel atoms. When forming clusters and at high doses, irradiation can increase the concentration of electroactive nickel atoms by 1,5÷2 of the order. This can serve as a method of controlling electroactive nickel atoms in silicon.

Thus, it can be argued that silicon with clusters of manganese and nickel atoms acquires a

sufficiently high radiation resistance. At high doses, the atoms of these impurities pass from the internode state to the nodes of the crystal lattice and become electroactive.

References

1. 
   Melvedskiy M.G., Chaldyshev V.V., Atomic nanoclusters in semiconductors. A novel approach to tailoring materials properties. FTP/ 1998, vol. 32, no .5, p.515.
   
2. 
   Abdurakhmanov B.A., Ayupov K.S., Bahadyrkhanov M.K., Iliev Kh.M., Bobonov D.T., Zikrillaev N.F., Saparniyazova Z.M., Toshev A. Low-temperature diffusion of impurities in silicon//Reports of the Academy of Sciences RUz. - Tashkent, 2010. - No. 4.- S. 34-38.
   
3. 
   M.K. Bakhadyrkhanov, K.S. Ayupov, H.M. Iliyev, G.H. Mavlonov, O.E. Sattarov. Influence of electric field, illumination and temperature on negative magnetoresistance in silicon alloyed by a method of "low- temperature diffusion"//Letters in Journals of technical science. – St. Petersburg, 2010. - T. 36 V. 16. - Page 11- 18.
   
4. 
   Bakhadyrkhanov M.K., Mavlonov G.K., Ayupov K.S., Isamov S.B. Negative magnetic resistance in silicon with complexes of manganese atoms//Physics and semiconductor technology. - St. Petersburg, 2010.- T. 44.- V. 9.- S. 1181-1184
   
5. 
   M.K.Bakhadirkhanov, G.Kh.Mavlonov, S.B.Isamov, K.S.Ayupov, Kh.M.Iliev, O.E Sattorov and ^{S.A.Tachilin «Photoconductivity of Silicon with Multicharged Clusters of Manganese Atoms [Mn]}4^{» USA,} Surface Engineering and Applited Electrohemistry, USA, 2010, Vol. 46. No.3, pp.276-280.
   
6. 
   Ayupov K.S., Bahadirkhanov M.K., Mavlyanov G.K., Zikrillaev N.F., Nigmankhujaev S. Activation of Nanoclusters of manganese atoms in silicon//Reports of the Academy of Sciences RUz. - Tashkent, 2009. - No. 3-4.- S. 56-58.
   

Rezyume. Olingan natijalar shuni ko‘rsatadi, p-tur o‘tkazuvchanlikli kremniyida marganets atomlari asosida nanoklasterlar yaratish bilan yuqori nurlanish dozalari sohasi uchun radiatsion barqaror material olish, nanoklasterlar shakllanishiga qadar ularning boshlang‘ich parametrlarini saqlash mumkin. Shuningdek, kremniyning nonoklasterlar bilan magnit va elektrlik xossalari Ф=10⁶÷10⁷R nurlanish dozasiga qadar etarlicha barqaror, shunday materiallar asosida tayyorlangan asbob-uskunalar yuqori dozalarda ham o‘z parametrlarini saqlab qoladi.

Резюме. Полученные результаты позволяют, что создавая нанокластеры на основе атомов марганца в кремнии р-типа проводимости можно получить радиационно устойчивый материал для области высоких доз облучения, сохранение его исходных параметров измереных до формирования нанокластеров. Также следует отметить, что магнитные и электрические свойства кремния с нанокластерами достаточно стабильны до дозы облучения Ф=10⁶10⁷ Р, а приборы изготовленные на основе таких материалов также не меняют свои параметры при высоких дозах облучения.
Kalit so‘zlar. Yarimo‘tkazgich materiallar, kirishma atom klasterlari, elektro-neytral va magnit klasterlari, γ – nurlanish.

Ключевые слова. Полупроводниковые материалы, кластеры примесных атомов, электронейтральные и магнитные кластеры, γ - облучение.