MeV Electron Irradiation of Ion-Implanted Si-SiO2 Structures

Abstract

The effect of (10-25) MeV electron irradiation on Si-SiO 2 structures implanted with different ions (Ar, Si, O, B, and P) has been investigated by different methods, such as deep-level transient spectroscopy (DLTS), thermo-stimulated current (TSCM), Rutherford backscattering (RBS), and soft X-ray emission spectroscopy (SXES). It has been shown that in double-treated Si-SiO 2 structures, the defect generation by high-energy electrons depends significantly on the location of preliminary implanted ions relative to the Si-SiO 2 interface as well as on the type (n-or p-Si) of silicon wafer. SiO 2 surface roughness changes, induced by ion implantation and high-energy electron irradiation of Si-SiO 2 structures, are observed by the atomic force microscopy (AFM). Si nanoclusters in SiO 2 of ion-implanted Si-SiO 2 structures generated by MeV electron irradiation is also discussed.

Swift heavy ion irradiation-induced amorphous iron and Fe–Si oxide phases in metallic 57Fe layer vacuum deposited on surface of SiO2/Si

“…The formation of amorphous iron by heavy ion irradiation depends not only on the irradiation conditions (ion type, energy and fluence of the ion) but also on the material and method of production of both the coating and the substrate. In the case of SiO 2 and Si which are frequently used as substrates for iron deposits, or in their multilayers with iron [20][21][22][23][24][25], different irradiation conditions induced the formation of various nanostructured phases [26][27][28][29][30][31][32][33][34][35][36][37].…”

Electron and Neutron Beam Irradiation Effects in Homogeneous and Nanostructured Oxides

“…The traditional model based on the obtained results assumes an irreversible conversion from E ′ γ to P b centers ( P b center is a trivalent Si atom playing role of fast trap) at the Si-SiO 2 interface through reactions with hydrogen molecules (hydrogen is released during long-term radiation exposure). Details on the generation of interface defects under MeV electron irradiation have been provided by a systematic investigation. , It has confirmed that 18 MeV electron irradiation generates new defects in the SiO 2 layer, most of which are positively charged oxygen vacancies (E′-centers). Besides, it generates various states at the Si/SiO 2 interface whose chemical nature and electronic position in the silicon band gap strongly depend on substrate doping .…”

“…Details on the generation of interface defects under MeV electron irradiation have been provided by a systematic investigation. 11,12 It has confirmed that 18 MeV electron irradiation generates new defects in the SiO 2 layer, most of which are positively charged oxygen vacancies (E′-centers). Besides, it generates various states at the Si/SiO 2 interface whose chemical nature and electronic position in the silicon band gap strongly depend on substrate doping.…”

“…It has been concluded that Si nanocrystals can be generated in SiO 2 by using electrons with energy higher than 150 keV or combining lower-energy electron irradiation with heating the specimen to achieve a temperature higher than the crystallization temperature of Si . Later experiments have shown that beams with electron energies higher than 1 MeV and much lower current densities (a few μA/cm 2 ; irradiation fluxes in the range from 5 × 10 11 to 5 × 10 13 electrons/cm 2 s) and electron fluences (around 10 14 to 10 17 electrons/cm 2 ) can also induce the formation of silicon nanoparticles in SiO 2 . ,, …”

“…21 Later experiments have shown that beams with electron energies higher than 1 MeV and much lower current densities (a few μA/ cm 2 ; irradiation fluxes in the range from 5 × 10 11 to 5 × 10 13 electrons/cm 2 s) and electron fluences (around 10 14 to 10 17 electrons/cm 2 ) can also induce the formation of silicon nanoparticles in SiO 2 . 10,11,19 The effect of 20 MeV electron beam irradiation on the phase separation and Si nanocluster formation in homogeneous SiO 1.2 and SiO 1.3 films has been investigated at fluences of 2.4 × 10 14 , 7.2 × 10 14 , 1.44 × 10 15 , and 3.6 × 10 15 electrons/cm 2 . 22,23 The irradiation at fluence of 7.2 × 10 14 electrons/cm 2 has led to small changes in the optical constants and the formation of very small amorphous Si (a-Si) nanoclusters.…”