V. M. Gusev

On silicon amorphization during different mass ion implantation

Abstract Amorphization of silicon single crystals during different mass 80 keV ions bombardment (B+, C+, Ne+, Ar+, Sb+) has been studied by means of three independent techniques, (a) ir absorption at 1.8 μ wave length (divacancy absorption), (b) ir reflection near a fundamental absorption edge, and (c) electron microscopy and fast electron diffraction. Irradiation was carried out at room temperature. From the analysis of data obtained it can be concluded that two types of disordered regions arise during ion bombardment, (a) amorphous regions (AR) and (b) disordered, but still possessing crystalline structure regions, which we call the crystalline disordered regions (CDR). In CDR the defect concentration is so high that divacancies do not appear. The defect concentration in CDR gradually increases with the increasing of irradiation dose. When the defect concentration achieves some critical value CDR transforms sharply to an amorphous state. Such amorphization mechanism prevails for light ions. For heavy io...

Effect of irradiation temperature on Si amorphization process

Abstract Some questions of the amorphization mechanism of semiconductors during ion bombardment have been considered theoretically. The probability of the formation of crystalline disordered regions (CDR) and amorphous regions (AR)1 has been calculated as a function of irradiation temperature T, atomic number Zi and ion enerw. It has been shown that the role of CDR in the amorphization process increases with the increase of T and decrease of Mi. The effect of irradiation temperature (T = −150, +25 and +1OO°C) on the silicon amorphization process during bombardment by light (B12), mean (Ne20) and heavy (Sb121) ions has been studied by various techniques: ir-absorption, ir-reflection and fast electron diffraction. It has been shown that the influence of irradiation temperature is stronger for light ions and large values of T. Theoretical results are in good agreement with experimental ones.

Helium blistering at high irradiation doses

Abstract The helium blistering on austenite steel and Cr-Ni alloy was investigated at ion energy 40 and 100 keV and at doses from 3. 1018 cm−2 to 1020 cm−2. A finite number of blister generations depending on ion-energy is observed. The diameter of blisters decreases from generation to generation and after the last generation of blisters the increase of doses results in sputtering of the surface and in formation of porous structure of the surface. Theoretical analysis shows: (i) blisters of subsequent generations can be formed only on places where blister covers of previous generations are opened; (ii) The blister diameter decreases from one generation to the next. Hence only a finite number of blister generations can be formed on a given surface. The number of possible blister generations is estimated as a function of ion energy.

AMORPHIZATION OF GERMANIUM CRYSTALS DURING ION BOMBARDMENT.

Abstract Germanium single crystal amorphization doses Da , during bombardment with 30 keV ions of different species (5⩽Zi;⩽83)are determined by a high energy electron diffraction method. The experimental dependence of the amorphization dose on ion atomic number is compared with the theoretical one, obtained on the assumption that the amorphous layer is formed as a result of an increase in the number and dimensions of microscopic amorphous zones produced by the bombarding ions. The character changes of the diffraction patterns for the lightest ions with dose differs from that for heavier ions. The temperature dependence of the amorphization dose for phosphorous ion bombardment in the range 10 °C ⩽ T ⩽ 250 °C is measured and compared with existing theories.

On Silicon Amorphisation During Different Mass Ions Implantation

Amorphisation of silico single crystals during different mass 80 keV ions bombardment (B+, C+, Ne+, Ar, Sb+) has been studied by means of three independent techniques, (a) IR absorption at I,8 μ wavelength (divacancy absorption), (b) IR reflection near a fundamental absorption edge, and (c) electron microscopy and fast electron diffraction. Irradiation was carried out at room temperature. From the analysis of data obtained it can be concluded that two types of disordered regions arise during ion bombardment, (a) amorphous regions (A.R.) and (b) disordered, but still processing crystalline structure regions; which we call the crystalline disordered regions (CDR). In CDR the defect concentration is so high that divacancies do not appear. The defect concentration in CDR gradually increases with the increasing of irradiation dose. When; the defect concentration achieves some critical value CDR transforms sharply to an amorphous state. Such amorphisation mechanism prevails for light ions. For heavy ions (Sb+) amorphisation arises mainly from a one-step AR formation. The proposed model of amorphisation gives the qualitative explanation of dose dependence of refractive index for different ions.