Epitaxial crystallization during 600 °C furnace annealing of amorphous Si layer deposited by low-pressure chemical-vapor-deposition and irradiated with 1-MeV Xe ions

Abstract

Articles you may be interested inThree-step growth of metamorphic GaAs on Si(001) by low-pressure metal organic chemical vapor depositionThe amorphous Si layers deposited by low-pressure chemical vapor deposition on ͑100͒-crystal-Si substrates and subjected to Xe-ion-beam irradiation are crystallized epitaxially in a layer-by-layer fashion to the surface during 600°C furnace annealing. Layer-by-layer crystallization can be accomplished by irradiating the layers with a 1-MeV Xe-ion-beam for a 2ϫ10 15 /cm 2 dose at 310°C prior to furnace annealing. In all cases during furnace annealing that amorphous Si layers are polycrystallized or are grown vertically in isolated epitaxial-columnar-structures and then grown laterally into the amorphous region surrounding each column, the ion-beam-induced epitaxial crystallization ͑IBIEC͒ method epitaxially crystallizes them in a layer-by-layer fashion. This is because O atoms that were at the initial interface and that prevented layer-by-layer crystallization or columnar-epitaxial-growth diffuse remarkably because of irradiation. This diffusion decreases the peak concentration and facilitates layer-by-layer crystallization. O atoms at the interface are also diffused by irradiation with 80-keV P, 100-keV As, and 150-keV As ions. This diffusion results in the columnar growth during 600-800°C furnace annealing. Whether layer-by-layer growth or columnar growth occurs during the furnace annealing depends on the peak concentration of oxygen at the interface. Direct evidence is shown that O diffusion is enhanced by the amount of inelastic electronic scattering of incident ion beam under the same elastic nuclear scattering conditions. The rates of IBIEC and of epitaxial crystallization during furnace annealing after 1-MeV Xe-ion-beam irradiation for a 2ϫ10 15 /cm 2 dose are affected by the amount of oxygen in the amorphous layer. The rate of layer-by-layer IBIEC using a 1-MeV Xe-ion-beam is nearly twice as high for a sample heated in the deposition furnace after evacuation as it is for a sample heated before evacuation. This difference is due to the smaller amount of oxygen in the amorphous Si layer of the former sample.

Comparison between Subsequent Irradiation and Co-Irradiation into SIMP Steel

“…Radiation-enhanced diffusion induces the Ostwald ripening of oxide nanoparticles in oxide dispersion strengthened (ODS) steels after Fe irradiation [ 33 ]. In addition, the decrease in the threshold temperature for recrystallization during ion collision of amorphous SiC based on the model of ion-beam-induced random nucleation has been reported [ 34 , 35 , 36 ], similar phenomenon reported in Si [ 37 ]. In addition, the decrease in total lattice disorder after ions implantation or swift-heavy ions irradiation has been observed in disordered SiC [ 32 , 38 , 39 , 40 , 41 , 42 ].…”

Epitaxial growth of a deposited amorphous Si layer formed on hydrogen-terminated Si(001) surfaces by ion beam induced epitaxial crystallization combined with ion beam mixing

“…In their previous reports, the accurate thickness and structure of the oxide layer and the exact amount of oxygen were not clearly shown and well defined. 23,25) In the present study, we prepared the well-defined hydride surfaces of DH and MH for the initial a/c interface and irradiated the same material of Si as a bulk element in IBMX preparation to clarify the substantial IBMX effect. It is because the IBMX preparation with Si ions can avoid the impurity effects, which was observed in the case of B, P and As implantation, in the crystallization process.…”

Thin-film transistors in polycrystalline silicon by blanket and local source/drain hydrogen plasma-seeded crystallization

“…Crystallization of amorphous silicon (a-Si), either as deposited or amorphized by ion implantation of as grown polysilicon, is an excellent precursor material for polysilicon films with large grain size and smooth surface [1]. Various techniques have been used to crystallize a-Si, namely solid phase crystallization (SPC) by annealing in a furnace [1] or a rapid thermal annealer [2] at temperatures in excess of 500 C, laser induced crystallization [3], ion-beam or electron-beam induced crystallization [4] or zone melt recrystallization [5]. Of these techniques, SPC has the advantage of high reproducibility and control of the device quality of the polysilicon films and of surface roughness.…”